Answer:
The bearing is N 55.62° W
Step-by-step explanation:
ship leaves the port of Miami with a bearing of S80°E and a speed of 15 knots.
It then turns 90° towards the south after one hour.
Still maintain the same speed and direction for two hours.
The bearing is just the angle difference from the ship current location to where it started.
Let the speed be km/h
Distance covered in the first round
= 15*1
= 15km
Distance covered in the second round
=15*2
= 30 km
Angle at C = (90-80)+90
Angle at C = 10+90= 100
Let the distance between the port and the ship be c
C²= a² + b² -2abcos
C²= 15²+30²-2(15)(30)cos 100
C²= 225+900+156.28
C²= 1281.28
C= 35.8 km
Using sine formula
30/sin x= 35.8/sin 100
30/35.8 * sin 100 = sinx
0.838*0.9848= sin x
0.8253= sin x
Sin ^-1 0.8253 = x
55.62° = x
The bearing is N 55.62° W
(16 points) Find the radius of convergence and the interval of convergence of the power series. g
Answer:
The equation to be solved is missing in the question.
I will explain power series and ways to find the radius and interval of convergence of a powers series in the attached image.
Step-by-step explanation:
Understand the power seriesFind radius of convergenceDetermine interval of convergenceAnswer Both Questions
Answer:is the first answer 15.875 and the second answer 17 x 28 ÷5
Step-by-step explanation:
Determine if the matrix is symmetric.
(-1 -5 -9 8)
The transpose of the given matrix is nothing. Because this is_____to the given matrix, the given matrix_____symmetric.
Answer:
because this is equal to the given matrix, the given matrix is symmetric.
Step-by-step explanation:
A symmetric matrix is a square matrix which has same number of rows and columns. Square matrix is equal to transpose. Equal matrices have equal dimensions. The given matrix is symmetric because the rows and columns are equally distributed.
!2,19,26 what comes nxt
Answer:
12 , 19 , 26 , 33
Explaination:Here, n+7
12+7=19
19+7=26
So,
26+7=33
Hope you understand ❣
Step-by-step explanation:
12 , 19 , 26 , ?
Given
___________
a1= 12
a2= 19
a3 = 26
d= ?
a4 = ?
––——————
we can solve this by using formula from Ap .
But for this we have to find d
As we know that
common difference(d) = a2-a1 = 19 -12
= 7
so difference after every no is 7 so
a4 = a3 + d
= 26 +7
= 33
So 33 is ur answer mate
Hope it helps
1) Dada a função, em reais, definida por f(x)=3.x-5. calcule :
a) f(2)=
b) f(-1)=
Answer:
f(x)= 3x-5
f(2) = 3(2)-5 = 6-5= 1
f(-1)= 3(-1)-5= -3-5= -8
Hope this helps
if u have question let me know in comments ^°^
are:
4. Suppose that the distance of fly balls hit to the outfield (in baseball) is normally
distributed. We randomly sample 27 fly balls. Their recorded distances in feet
234, 310, 285, 249, 210, 311, 265, 290, 308,
254, 295, 287, 231, 302, 325, 308, 221, 237,
312, 277, 259, 223, 340, 204, 214, 303, 309
Let X be the distance of a fly ball.
Use Excel to calculate the following:
a. (1 pt) mean of the sample, x =
b. (1 pt) standard deviation of the sample, s =
C. (2 pts) Calculate the t-score at a 96% confidence level:
d. (2 pts) Calculate the Error Bound (EBM), using the formula, EBM =
(t)(s//n)
e. (1 pt) At 96% confidence level, provide the confidence interval (CI) for the
mean distance in feet of a fly ball.
hantor 92
D
Step-by-step explanation:
a. The mean can be found using the AVERAGE() function.
x = 272.7
b. The standard deviation can be found with the STDEV() function.
s = 39.9
c. The t-score can be found with the T.INV.2T() function. The confidence level is 0.04, and the degrees of freedom is 26.
t = 2.162
d. Find the lower and upper ends of the confidence interval.
Lower = 272.7 − 2.162 × 39.9 = 186.5
Upper = 272.7 + 2.162 × 39.9 = 358.9
If 6x +3= 2x+ 19, then x =
Answer:
x = 4
Step-by-step explanation:
6x + 3 = 2x + 19 ------ subtract 3 both sides
6x + 3 - 3 = 2x + 19 - 3 simplify
6x = 2x + 16 ------ subtract 2x both sides
6x - 2x = 2x + 16 - 2x simplify
4x = 16
x = 16 / 4
x = 4
Answer: x = 4
Step-by-step explanation: If the variable appears on both sides of the equation, we put the variables together on one side of the equation and the numbers together on the other side of the equation.
So let's put our variables on the left side by first subtracting
2x from both sides of the equation to get 4x + 3 = 19.
Next, we subtract 3 from both sides to get 4x = 16.
Finally, we divide both sides by 4 to get x = 4.
Find the mean of the data summarized in the given frequency distribution. Compare the computed mean to the actual mean of 51.1 degrees. Low Temperature (◦F) 40−44 45−49 50−54 55−59 60−64 Frequency 3 6 13 7
Answer:
[tex]Mean = 53.25[/tex]
Step-by-step explanation:
Given
Low Temperature : 40−44 || 45−49 || 50−54 || 55−59 || 60−64
Frequency: --------------- 3 -----------6----------- 1-----------3--- -----7
Required
Determine the mean
The first step is to determine the midpoints of the given temperatures
40 - 44:
[tex]Midpoint = \frac{40+44}{2}[/tex]
[tex]Midpoint = \frac{84}{2}[/tex]
[tex]Midpoint = 42[/tex]
45 - 49
[tex]Midpoint = \frac{45+49}{2}[/tex]
[tex]Midpoint = \frac{94}{2}[/tex]
[tex]Midpoint = 47[/tex]
50 - 54:
[tex]Midpoint = \frac{50+54}{2}[/tex]
[tex]Midpoint = \frac{104}{2}[/tex]
[tex]Midpoint = 52[/tex]
55- 59
[tex]Midpoint = \frac{55+59}{2}[/tex]
[tex]Midpoint = \frac{114}{2}[/tex]
[tex]Midpoint = 57[/tex]
60 - 64:
[tex]Midpoint = \frac{60+64}{2}[/tex]
[tex]Midpoint = \frac{124}{2}[/tex]
[tex]Midpoint = 62[/tex]
So, the new frequency table is as thus:
Low Temperature : 42 || 47 || 52 || 57 || 62
Frequency: ----------- 3 --||- -6-||- 1-||- --3- ||--7
Next, is to calculate mean by
[tex]Mean = \frac{\sum fx}{\sum x}[/tex]
[tex]Mean = \frac{42 * 3 + 47 * 6 + 52 * 1 + 57 * 3 + 62 * 7}{3+6+1+3+7}[/tex]
[tex]Mean = \frac{1065}{20}[/tex]
[tex]Mean = 53.25[/tex]
The computed mean is greater than the actual mean
GIVING OUT BRAINLIEST TO THE FIRST PERSON TO ANSWER!!
One circle has a diameter of 6 inches. A second, larger circle has a diameter that is four times the diameter of the first circle. What is the ratio of the area of the smaller circle to the larger circle?
A. 2:3
B. 1:6:4
C. 1:16
D. 1:64
Please include ALL work! <3
Answer:
The answer is option CStep-by-step explanation:
To find the ratio first find the diameter of the larger circle
Diameter of first circle = 6 inches
Diameter of second circle = 4 × diameter of the first circle
Which is
Diameter of second circle
= 4 × 6 = 24 inches
Area of a circle = πr²
r is the radius
Area of smaller circle
Diameter = 6 inches
Radius = 6 / 2 = 3 inches
Area = (3)² π = 9π in²
Area of larger circle
Diameter = 24 inches
Radius = 24 / 2 = 12 inches
Area = (12)²π = 144π in²
The ratio of the smaller circle to the larger circle is
[tex] \frac{9\pi}{144\pi} [/tex]
Reduce the fraction by 9π
That's
[tex] \frac{1}{16} [/tex]
We have the final answer as
1 : 16Hope this helps you
Answer:
C. 1:16
Step-by-step explanation:
Area of a circle is:
[tex]\pi \times {r}^{2} [/tex]
Small circle Area:
radius = diameter/2
radius = 6/2 = 3
[tex]area \: of \: a \: circle \: = \pi {3}^{2} [/tex]
a = 28.27
Large circle 4 times larger diameter
6*4 = 24
diameter = 24
r = 24/2
r = 12
[tex]a \: = \pi {12}^{2} [/tex]
a = 452.39
area of large circle/ area of small circle
452.39/28.27 = 16.00
ratio is 1:16
CALC 1: Spud's mom is going to make him a round birthday cake, and has asked for your help. Spud is a bit weird, and has already
announced that when he slices the cake, your slice will have a perimeter of 16 inches, because you're his favorite friend, and
that's his favorite number. Since you're helping his mom with the baking, what diameter cake will you recommend she makes
so that you end up with the most possible cake at weird Spud's party? (Hint: you can ignore the thickness df the cake, since
this will be the same, regardless of its diameter.)
10.1
in
Answer:
15.7 in
Step-by-step explanation:
A slice of a round pie is a sector of a circle.
The perimeter of a slice is the arc length s plus twice the radius r.
P = s + 2r
s = rθ = r(16/360) = r/22.5. So,
16 = (r/22.5) + 2r = (r + 45r)/22.5 = 46r/22.5
16 × 22.5 = 46r
360 = 46r
r = 7.826
D = 2r = 2 × 7.826 = 15.7 in
The diameter of the cake should be 15.7 in.
Check:
[tex]\begin{array}{rcl}P & = & s + 2r\\& = & \dfrac{r}{22.5} + 2r\\\\16 & = & \dfrac{7.826}{22.5} + 2 \times 7.826\\\\16 & = & 0.35 + 15.65\\16 & = & 16.00\\\end{array}[/tex]
It checks.
Shyla's research shows that 8 empty cans make 1/4 pound of aluminum. Shyla wants to know how many cans does it take to make 5 pounds of aluminum. How many cans are there per pound of aluminum?
Answer:
They will need 160 cans to make 5 lbs
32 cans for 1 lbs
Step-by-step explanation:
We can use ratios to solve
8 cans x cans
--------------- = ---------------
1/4 lbs 5 lbs
Using cross products
8 * 5 = 1/4x
40 = 1/4 x
Multiply each side by 4
4 * 40 = 1/4 x * 4
160 =x
They will need 160 cans to make 5 lbs
8 cans x cans
--------------- = ---------------
1/4 lbs 1 lbs
Using cross products
8 * 1 = 1/4x
Multiply each side by 4
8*4 = x
32 cans for 1 lbs
Answer:
32 cans per pound of aluminum
160 cans per 5 pounds of aluminum
Step-by-step explanation:
will make it short and simple.
8 empty cans can make 1/4 pound of aluminum.
therefore... 8 x 4 = 32 cans per pound of aluminum.
Number of cans to make 5 pounds of aluminum = 32 x 5
= 160 cans per 5 pounds of aluminum
find x, if sq.root(x) +2y^2 = 15 and sq.root(4x) - 4y^2=6
Answer:
Example: solve √(2x−5) − √(x−1) = 1
isolate one of the square roots:√(2x−5) = 1 + √(x−1) square both sides:2x−5 = (1 + √(x−1))2 ...
expand right hand side:2x−5 = 1 + 2√(x−1) + (x−1) ...
isolate the square root:√(x−1) = (x−5)/2. ...
Expand right hand side:x−1 = (x2 − 10x + 25)/4. ...
Multiply by 4 to remove division:4x−4 = x2 − 10x + 25.
Answer:
Step-by-step explanation:
ewrerewrwrwerrwer
An investigator claims, with 95 percent confidence, that the interval between 10 and 16 miles includes the mean commute distance for all California commuters. To have 95 percent confidence signifies that
Answer:
Hello the options to your question is missing below are the options
A) if sample means were obtained for a long series of samples, approximately 95 percent of all sample means would be between 10 and 16 miles
B.the unknown population mean is definitely between 10 and 16 miles
C.if these intervals were constructed for a long series of samples, approximately 95 percent would include the unknown mean commute distance for all Californians
D.the unknown population mean is between 10 and 16 miles with probability .95
Answer : if these intervals were constructed for a long series of samples, approximately 95 percent would include the unknown mean commute distance for all Californians ( c )
Step-by-step explanation:
95% confidence
interval = 10 to 16 miles
To have 95% confidence signifies that if these intervals were constructed for a long series of samples, approximately 95 percent would include the unknown mean commute distance for all Californians
confidence interval covers a range of samples/values in the interval and the higher the % of the confidence interval the more precise the interval is,
Find an equation of the tangent to the curve at the given point by both eliminating the parameter and without eliminating the parameter. x = 5 + ln(t), y = t2 + 2, (5, 3)
Answer:
Step-by-step explanation:
Given that:
[tex]x = 5 + In (t)[/tex]
[tex]y = t^2+2[/tex]
At point (5,3)
To find an equation of the tangent to the curve at the given point,
By without eliminating the parameter
[tex]\dfrac{dx}{dt}= \dfrac{1}{t}[/tex]
[tex]\dfrac{dy}{dt}= 2t[/tex]
[tex]\dfrac{dy}{dx}= \dfrac{ \dfrac{dy}{dt} }{\dfrac{dx}{dt} }[/tex]
[tex]\dfrac{dy}{dx}= \dfrac{ 2t }{\dfrac{1}{t} }[/tex]
[tex]\dfrac{dy}{dx}= 2t^2[/tex]
[tex]\dfrac{dy}{dx}_{ (5,3)}= 2t^2_{ (5,3)}[/tex]
t² + 5 = 4
t² = 4 - 5
t² = - 1
Then;
[tex]\dfrac{dy}{dx}_{ (5,3)}= -2[/tex]
The equation of the tangent is:
[tex]y -y_1 = m(x-x_1)[/tex]
[tex](y-3 )= -2(x - 5)[/tex]
y - 3 = -2x +10
y = -2x + 7
y = 2x - 7
By eliminating the parameter
x = 5 + In(t)
In(t) = 5 - x
[tex]t =e^{x-5}[/tex]
[tex]y = (e^{x-5})^2+5[/tex][tex]y = (e^{2x-10})+5[/tex]
[tex]\dfrac{dy}{dx} = 2e^{2x-10}[/tex]
[tex]\dfrac{dy}{dx}_{(5,3)} = 2e^{10-10}[/tex]
[tex]\dfrac{dy}{dx}_{(5,3)} = 2[/tex]
The equation of the tangent is:
[tex]y -y_1 = m(x-x_1)[/tex]
[tex](y-3 )= -2(x - 5)[/tex]
y - 3 = -2x +10
y = -2x + 7
y = 2x - 7
Find the Value of X 1. Solve for X algebraically. 2. Using complete sentences, describe your method for finding X.
The value of x using complete sentences is 40 degrees.
What is the angle sum property?The angle sum property of a triangle states that the sum of the interior angles of a triangle is 180 degrees. A right-angle triangle is a triangle that has a side opposite to the right angle the largest side and is referred to as the hypotenuse. The angle of a right angle is always 90 degrees.
We are given that;
The measure of angles 75,50 and 85
Now,
In triangle 1
50+75+y=180
y=180-125
y=55
In triangle 2
55+85+x=180
140+x=180
x=40
Therefore, by angle sum properties of triangle answer will be 40 degrees.
Learn more about the triangles;
https://brainly.com/question/2773823
#SPJ3
given that f(x)=x^2-4x -3 and g(x)=x+3/4 solve for f(g(x)) when x=9
Answer:
f(g(9)) = 945/16
Step-by-step explanation:
To find f(g(x)), you have to substitute g(x) wherever there is an x in f(x).
g(x) = x + 3/4
f(x) = x² - 4x - 3
f(g(x)) = (x + 3/4)² - 4(x + 3/4) - 3
f(g(x)) = x² + 3/2x + 9/16 - 4x + 3 - 3
f(g(x)) = x² - 5/2x + 9/16 + 3 - 3
f(g(x)) = x² - 5/2x + 9/16
Now, put a 9 wherever there is an x in f(g(x)).
f(g(9)) = (9)² - 5/2(9) + 9/16
f(g(9)) = 81 - 5/2(9) + 9/16
f(g(9)) = 81 - 45/2 + 9/16
f(g(9)) = 117/2 + 9/16
f(g(9)) = 945/16
A survey of 1,565 households estimated that 72% of the households in a given state owned a television. What is the population? all the households in given state 1565 households surveyed 1127 households that owned televisions
Answer:
all the houses in given state
Step-by-step explanation:
edge 2021
Using sampling concepts, it is found that the population is given by:
All the households in given state.
What is a sampling?In a sampling, data is taken from a sample to be estimated for the entire population.
For example, if you want to find the proportion of New York State residents that are Buffalo Bills fans, surveying a sample of 1000 residents, the population is all New York State residents.
Hence, in this problem, the population is given by all the households in given state.
More can be learned about sampling concepts at https://brainly.com/question/25122507
Fill in the following blanks to prove that n 2^1 n < 2^n n+1 < 2^(n+1) is Box 3 Options: True | False Next, assume that Box 4 Options: 1 < 2^1 k + 1 < 2^(k+1) k < 2^k as we attempt to prove Box 5 Options: k < 2^k k + 1 < 2^(k+1) 2 < 2^1 Therefore, we can conclude that Box 6 Options: k < 2^k k + 1 < 2^(k+1) 2^1 < 2^k k + 2 < 2^(k+2)
Answer:
see below
Step-by-step explanation:
n < 2^n
First let n=1
1 < 2^1
1 <2 This is true
Next, assume that
(k) < 2^(k)
as we attempt to prove that
(k+1) < 2^(k+1)
.
.
.
Therefore we can conclude that
k+1 < 2^(k+1)
Answer:
Step-by-step explanation:
Hello, please consider the following.
First, assume that n equals [tex]\boxed{1}[/tex]. Therefore, [tex]\boxed{1<2^1}[/tex] is [tex]\boxed{\text{True}}[/tex]
Next, assume that [tex]\boxed{k<2^k}[/tex], as we attempt to prove [tex]\boxed{k+1<2^{k+1}}[/tex]
Since .... Therefore, we can conclude that [tex]\boxed{k+1<2^{k+1}}[/tex]
The choice for the last box is confusing. Based on your feedback, we can assume that we are still in the step 2 though.
And the last step which is not included in your question is the conclusion where we can say that we prove that for any integer [tex]n\geq 1[/tex], we have [tex]n<2^n[/tex].
Hope this helps.
Do not hesitate if you need further explanation.
Thank you
Let REPEAT TM = { | M is a TM, and for all s ∈ L(M), s = uv where u = v }. Show that REPEATTM is undecidable. Do not use Rice’s Theorem.
Answer:
Step-by-step explanation:
Let REPEAT [tex]_{TM[/tex]= { | M is a TM, and for all s ∈ L(M), s = uv where u = v }
To prove that REPEAT [tex]_{TM[/tex] is undecidable.
Let REPEAT [tex]_{TM[/tex] {| M is a TM that does not accept M}
Then, we form a TM u for L by applying TM v as a subroutine.
Assume Repeat is decidable
Let M be the algorithm that TM which decides the REPEATU = on input "s" simulate the M
Accept; if M ever enters the accept state
Reject; if M ever enters the reject state
U does not decide the REPEAT as it may loop over s
so REPEAT is undecidable
The perimeter of a rectangular garden is 43.8 feet. It's length is 12.4t . What is it's width ?
Answer:5
Step-by-step explanation:
A line passes through (-5, -3) and is parallel to -3x - 7y = 10. The equation of the line in slope-intercept form is _____
Answer:
-3x - 7y = 36
Step-by-step explanation:
The given line -3x - 7y = 10 has an infinite number of parallel lines, all of the form -3x - 7y = C.
If we want the equation of a line parallel to -3x - 7y = 10 that passes through (-5, -3), we substitute -5 for x in -3x - 7y = 10 and substitute -3 for y in -3x - 7y = 10:
-3(-5) - 7(-3) = C, or
15 + 21 = C, or C = 36
Then the desired equation is -3x - 7y = 36.
what is the least number to be added to 1500 to make it a perfect square?
Answer:
21
Step-by-step explanation:
√1500 ≈ 38.7
round that up to 39 and square it:
39² = 1521
A baking scale measures mass to the tenth of a gram, up to 650 grams. Which of the following measurements is possible using this scale? a.3.8 grams b.120.01 grams c.800.0 grams d.54 milligrams
Answer:
Step-by-step explanation:
The answer is b
120.01 grams
The red blood cell counts (in millions of cells per microliter) for a population of adult males can be approximated by a normal distribution, with a mean of million cells per microliter and a standard deviation of million cells per microliter. (a) What is the minimum red blood cell count that can be in the top % of counts? (b) What is the maximum red blood cell count that can be in the bottom % of counts?
Answer:
(a) Minimum red blood cells 5.744 million cells per micro liter
(b) Maximum red blood cells 5.068 million cells per micro liter.
Step-by-step explanation:
Z-score formula is = [tex]\frac{x-u}{Standard deviation}[/tex]
Z-score = [tex]\frac{x-5.5}{0.4}[/tex]
The value of z-score is 0.61 so then x will be;
x = 5.744
The minimum red blood cells count that can in top is 27% of count which is 5.744 million cells per micro liter.
Z-score = [tex]\frac{x-5.5}{0.4}[/tex]
The value of z-score is 0.14 so then x will be;
x = 5.068
The maximum red blood cells count that can be in top is 14% of count which is 5.068 million cells per micro liter.
I’m struggling to understand this problem somebody please explain it to me thanks!!
ax-5d=3cx-2+7
Answer:
x = (5 +5d)/(a -3c)
Step-by-step explanation:
Maybe you're to solve for x.
__
This is a typical "3-step" linear equation.
First, you collect terms with the variable x on one side of the equation. You do that by subtracting from both sides the x-term you don't want where it is.
We choose to remove the 3cx term from the right side, so we subtract it from both sides.
ax -3cx -5d = 3cx -3cx +5 . . . . . . we have combined the constants, too
x(a -3c) -5d = 5 . . . . . . simplify and factor out x
Second, you remove any terms not containing x from the side of the equation with the x-terms. You do that by adding their opposite to both sides of the equation.
We need to remove the -5d term, so we add 5d to both sides.
x(a -3c) -5d +5d = 5 +5d
x(a -3c) = 5 +5d . . . . . . . . . . simplify
Third, we divide by the coefficient of x. We do that to both sides of the equation. We had to put parentheses around the terms on the right, because we're dividing the whole right side of the equation by (a-3c).
x(a -3c)/(a -3c) = (5 +5d)/(a -3c)
x = (5 +5d)/(a -3c)
Please help. I’ll mark you as brainliest if correct!
Answer:
(DNE,DNE)
Step-by-step explanation:
-24x-12y = -16. Equation one
6x +3y = 4. Equation two
Multiplying equation two with +4 gives
4(6x +3y = 4)
24x +12y = 16...result of equation two
-24x -12y= -16...
A careful observation to the following equation will help us notice that the both equation are same thing.
Multiplying minus to equation one gives
-(-24x-12y=-16)
24x+12y = 16.
Since the both equation are same, there is no solution to it.
Identify the sample space of the probability experiment and determine the number of outcomes in the sample space. Playing the game of roulette, where the wheel consists of slots numbered 00, 0, 1, 2, ..., To play the game, a metal ball is spun around the wheel and is allowed to fall into one of the numbered slots.a. The sample space is (00, 0}. b. The sample space is (00, 0, 1,2,., 33). c. The sample space is (00). d. The sample space is (1, 2,..., 33).
Answer:
The correct option is (B).
Step-by-step explanation:
It is provided that, in a game of roulette the wheel consists of slots numbered 00, 0, 1, 2, ..., 33.
The sample space of an experiment, is the set of all the possible outcomes of the random trials.
There are a total of 35 slots on the roulette wheel where the ball can land.
So, there are a total of 35 outcomes for one rotation of the wheel.
Then the sample space consists of all the 35 outcomes, i.e.
S = {00, 0, 1, 2, 3, ..., 33}
Thus, the correct option is (B).
Please help . I’ll mark you as brainliest if correct!
Answer:
Stocks = $15,500
Bonds = $107,250
CD's = $47,250
Step-by-step explanation:
S + B + C = 170000
.0325S + .038B .067C = 7745
60,000 + C = b
S = $15,500
B = $107,250
C = $47,250
HELP ME ILL GIV ROBUX Identify the property shown by the equation. 14 × 6 = 6 × 14 A. Commutative Property B. Associative Property C. Identity Property D. Distributive Property PLEASE HELP ME
Answer:
Its commutative property..
Step-by-step explanation:
Commutative property says A×B=B×A
Explanation is attached below.
Twice the difference of a number and 9 is 3. Use the variable b for the unknown number.
Answer:
b = 10.5
Step-by-step explanation:
2(b-9) = 3
then:
2*b + 2*-9 = 3
2b - 18 = 3
2b = 3 + 18
2b = 21
b = 21/2
b = 10.5
check:
2(10.5 - 9) = 3
2*1.5 = 3
