7(x+1)=21 solve for x

Answer:

x = 2

Step-by-step explanation:

Probability that the marble comes to rest in the shaded region is equal to the ratio of the shaded area to the total area.

Probability 'P' = [tex]\frac{A'}{A}[/tex]

Area of the shaded region (A')= (x + 1)(x + 2)

Total area of the figure (A) = (2x + 1)(3x + 2)

P = [tex]\frac{(x+1)(x+2)}{(2x+1)(3x+2)}=\frac{3}{10}[/tex]

10(x + 1)(x + 2) = 3(2x + 1)(3x + 2)

10(x² + 3x + 2) = 3(6x² + 7x + 2)

10x² + 30x + 20 = 18x² + 21x + 6

(18x² - 10x²) + (21x - 30x) + (6 - 20) = 0

8x² - 9x - 14 = 0

x = [tex]\frac{9\pm\sqrt{(-9)^2-4(8)(-14)} }{2(8)}[/tex]

x = [tex]\frac{9\pm \sqrt{81+448}}{16}[/tex]

x = [tex]\frac{9\pm 23}{16}[/tex]

x = -[tex]\frac{7}{8}, 2[/tex]

Therefore, positive value of x = 2 will be the answer.

Zoologists are studying two newly discovered species of insects in a previously unexplored section of rain forest. They estimate the current population of insect A to be 1.3 million and the current population of insect B to be 2.1 million. As development is encroaching on the section of rain forest where these insects live, the zoologists estimate the populations of insect A to be reducing at a rate of 3.8% and insect B to be reducing at a rate of 4.6%.

If P represents the population of each species of insect in millions, and t represents the elapsed time in years, then which of the following systems of equations can be used to determine how long it will be before the populations of the two species are equal?

Answer:

the  system of equation that  can be used to determine how long it will be before the populations of the two species are equal is :

[tex]\begin{cases} {\mathtt{P = 1.3 e^{-0.038 \ t}} & \\ \mathtt{P = 2.1 \ e^{-0.046 \ t}} & \end{cases}[/tex]

Step-by-step explanation:

Given that :

the current population of insect A to be 1.3 million

the current population of insect B to be 2.1 million.

As development is encroaching on the section of rain forest where these insects live, the zoologists estimate the populations of insect A to be reducing at a rate of 3.8% and insect B to be reducing at a rate of 4.6%.

The equation that can be used to determine how long it will be before the populations of the two species are equal is an equation for exponential decay, which can be represented as follows:

[tex]\mathtt{y = pe^{-rt}}[/tex]

where;

P represents the population of each species of insect in millions

t represents the elapsed time in years

r is the rate of decrease

So, we can have:

[tex]\mathtt{p_1 = 1.3 }[/tex] in million   and  [tex]\mathtt{p_2 = 2.1}[/tex] in million

Also for rate of decrease;

[tex]\mathtt{r_1 = 0.038}[/tex]     and [tex]\mathtt{r_2 = 0.046}[/tex]

Therefore;

the exponential decay for Population of insect A can now be:

[tex]\mathtt{P = 1.3 e^{-0.038 \ t}}[/tex]

the exponential decay for Population of insect B can now be:

[tex]\mathtt{P = 2.1 \ e^{-0.046 \ t}}[/tex]

Hence, the  system of equation that  can be used to determine how long it will be before the populations of the two species are equal is :

[tex]\begin{cases} {\mathtt{P = 1.3 e^{-0.038 \ t}} & \\ \mathtt{P = 2.1 \ e^{-0.046 \ t}} & \end{cases}[/tex]

Answer:

A!

Step-by-step explanation:

Plato

Answer:

trerjyhtrwgfdfeqrtgfnerwqdfgfgrqwefgn

Step-by-step explanation:

Answer:

a

Step-by-step explanation:

a because when you divide 80 by 12 you get 28, so then it is 12 x 28m. :/

Answer:

Width  W = 14 m

Length  L = 26 m

Step-by-step explanation:

Perimeter of a rectangle = 80 m = 2L + 2W

L = 12 + W

80 = 2L + 2W

80 = 2(12 + W) + 2W

80 = 24 + 2W + 2W

80 - 24 = 4W

56 = 4W

W = 56 / 4

W = 14 m

L = 12 + W

L = 12 + 14

L = 26 m

check:

80 = 2L + 2W

80 = 2(26) + 2(14)

80 = 52 + 28

80 = 80 ---- OK

Answer:

See attached

Step-by-step explanation:

13450 = 13000 + 400 + 50

Answer: (1, −5)

Step-by-step explanation:

Plot the given inequalities on coordinate plane.

For y < −3x + 3, plot y =−3x + 3

At x=0,  y= 3

At y =0, 0=-3x+3

⇒ x= 1

so, plot points (0,3) and (1,0) and join to get y =−3x + 3, since inequality has '<' sign, so shade( in red) below line area and line should be dotted.

For  y < x + 2, plot  y = x + 2

At x=0,  y= 2

At y =0, x=-2

so, plot points (0,2) and (-2,0) and join to get y = x + 2, since inequality has '<' sign, so shade( in orange) below line area and line should be dotted.

Now, plot all given points (1, −5) (1, 5) (5, 1) (−1, 5), we can clearly observe that (1, −5) lies in the solution set.  (in common shaded region)

Answer:

The correct answer is 1, -5

Step-by-step explanation:

Answer:

n/2>8

Step-by-step explanation:

Half of N is N/2

And if 8 is less that half of N or N/2

then

N/2 has to be greater than 8

N/2>8

Answer: Solution: [tex]a=\dfrac{-19}{3}[/tex] and [tex]b=\dfrac{1}{3}[/tex] .

Step-by-step explanation:

The given pair of equations:

[tex]a-8b= -9\ ...(i)\\\\ a-2b= -7\ ...(ii)[/tex]

Eliminate equation (i) from (ii) , we get

[tex]-2b-(-8b)=-7-(-9)\\\\\Rightarrow\ -2b+8b=-7+9\\\\\Rightarrow\ 6b=2\\\\\Rightarrow\ b=\dfrac{1}{3}[/tex]

Put value of b in (ii) , we get

[tex]a-2\times\dfrac{1}{3}=-7\\\\\Rightarrow\ a=-7+\dfrac{2}{3}\\\\\Rightarrow\ a=\dfrac{-21+2}{3}\\\\\Rightarrow\ a=\dfrac{-19}{3}[/tex]

Solution: [tex]a=\dfrac{-19}{3}[/tex] and [tex]b=\dfrac{1}{3}[/tex] .

Answer:

The correct option is;

y < x - 2, and y > x + 1

Step-by-step explanation:

The given graph of inequalities is made up of parallel lines. Therefore, the slope of the inequalities are equal

By examination of the graph, the common slope = (Increase in y-value)/(Corresponding increase in x-value) = (0 - 1)/(-1 - 0) = 1

Therefore, the slope = 1

We note that the there are three different colored regions, therefore, the different colored regions opposite to each inequalities should be the areas of interest

The y-intercept for the upper bounding linear inequality, (y >) is 1

The y-intercept for the lower bounding linear inequality, (y <) is -2

The two inequalities are y > x + 1 and y < x - 2

The correct option is y < x - 2, and y > x + 1.

The system of linear inequalities is represented by  the graph is y> x-2 and y < x + 1

Inequalities is an expression that shows the non equal comparison of two or more variables and numbers.

Given that:

The system of linear inequalities is represented by  the graph is y> x-2 and y < x + 1

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Answer:

1.015

Step-by-step explanation:

just find their average, which is adding them up and dividing by 2

(1.01 + 1.02)/2 = 1.015

The decimal number exactly halfway between 1.01 and 1.02 is 1.015.

A decimal numeral system is the standard system for denoting integer and non-integer numbers. The way of denoting numbers in the decimal system is often referred to as decimal notation.

The given numbers are,

1.01 and 1.02

Now to find the halfway between the number we need to find their sum first and then the half of the sum.

So, the sum of number,

1.01 + 1.02 = 1.03

Now for half way divide the sum by 2

1.03/2 = 1.015

Hence, The decimal number exactly halfway between 1.01 and 1.02 is 1.015.

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Answer:

we need more information

Step-by-step explanation:

Answer:

The correct option is;

B. N'(1, 0), U'(3, 5), L'(5, 2), H'(3, -2)

Step-by-step explanation:

The coordinates of the pre-image are given as follows;

H(1, -5), N(-1, -3), U(1, 2), and L(3, -1)

The required transformation is T₍₂, ₃₎,which is a translation of (two) 2 units right and an additional  translation of (three) 3 units up, which gives the coordinates of the image as follows;

N(-1, -3) transformed by N(-1 + 2, -3 + 3)  [tex]\overset{T_{(2,\, 3)}}{\rightarrow}[/tex] N'(1, 0)

U(1, 2) transformed by U(1 + 2, 2 + 3)  [tex]\overset{T_{(2,\, 3)}}{\rightarrow}[/tex] U'(3, 5)

L(3, -1) transformed by L(3 + 2, -1 + 3)  [tex]\overset{T_{(2,\, 3)}}{\rightarrow}[/tex] L'(5, 2)

H(1, -5) transformed by H(1 + 2, -5 + 3)  [tex]\overset{T_{(2,\, 3)}}{\rightarrow}[/tex] H'(3, -2)

The coordinates of the vertices of the given figure after the given transformation, T₍₂, ₃₎, are N'(1, 0), U'(3, 5), L'(5, 2), and H'(3, -2).

Therefore, the correct option is N'(1, 0), U'(3, 5), L'(5, 2), H'(3, -2).

Answer:

21

Step-by-step explanation:

4[tex]\frac{1}{5}[/tex] = [tex]\frac{21}{5}[/tex]

5 × [tex]\frac{21}{5}[/tex] = (5×21)/5

[tex]\frac{105}{5}[/tex] = 21

Hey there! I'm happy to help!

When building equations, the word "is" means "equals".

First, we have the sum of a number and six. You can use any letter to represent the number. I will use n.

(n+6)

We see that this is multiplied by 5. We can just put the 5 next to the parentheses. This shows multiplication.

5(n+6)

Is 48

5(n+6)=48

Have a wonderful day! :D

The statements that can be used to describe the reasoning used to determine if Kelsey’s inequality is correct include:

It should be noted that the inequality symbol is incorrect because she can spend up to and including $65.

Based on the information given, the correct expression that can be used to solve the question should be:

65 - (5.50b + 7.5)

In conclusion, the correct options are B and C.

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Answer:

B and C

Step-by-step explanation:

Answer:

C: Function 2 has the larger maximum at (2, 5).

Step-by-step explanation:

We are given two functions, with Function 1 being described by the graph and Function 2 given by the function:

[tex]f(x)=-x^2+4x+1[/tex]

Notice that the leading coefficient of Function 2 is negative. The graph of Function 1 is curving downwards. So, both functions will have maximum values.

Recall that for a parobala, the maximum (or minimum) values is the y-value of the vertex point. So, let's find the vertex for each function.

For Function 1, we can see that the vertex is at (4,1). Thus, its maximum value is y = 1.

For Function 2, we will need to work out the vertex. Recall that the vertex is given by:

[tex]\displaystyle \left(-\frac{b}{2a},f\left(-\frac{b}{2a}\right)\right)[/tex]

Function 2 is defined by:

[tex]f(x)=-x^2+4x+1[/tex]

Therefore, a = -1, b = 4, and c = 1.

Find the x-coorindate of the vertex:

[tex]\displaystyle x=-\frac{(4)}{2(-1)}=2[/tex]

Substitute this back into the function to find the y-coordinate.

[tex]f(2)=-(2)^2+4(2)+1=5[/tex]

So, the vertex of Function 2 is (2,5). Therefore, the maximum value of Function 2 is y = 5.

Since 5 is greater than 1, the maximum value of Function 2 is greater.

The answer is choice C.

Answer:a

Step-by-step explanation:

Answer:

length = 100

width = 25

Step-by-step explanation:

Let L = length of red rectangle

Let H = height of red rectangle

Equation1:   L+H=125 : we know the perimeter is 250 so L+H is 125

Equation2:   L*H=2,500 : we know the area is 2,500

Equation3:   L=125-H : subtracted H from both sides of Equation1

Equation4:   (125-H)*H=2,500 : substituted "125-H" for L into Equation2

Solve equation4:

  (125-H)*H=2,500   multiple terms on left side of equation

  125H - H^2 = 2,500   rearrange into standard form

  H^2 - 125H + 2,500 = 0

At this point you can "brute force" the answer with the quadratic formula:

H = (125 ± SQRT(125^2 - 4*1*2500) ) / 2

H = 100 or H = 25 : actually these are L and H

You could also factor the equation:

(H - 100) * (H - 25) = 0 : gives same answe

Answer:

Around 18.18%

Step-by-step explanation:

We can use the percentage increase formula to find the gain here. The formula goes:

[tex]\frac{new-original}{original}\cdot100[/tex].

We know that the new value is 6500, and the old value is 5500, so we can substitute inside the equation.

[tex]\frac{6500-5500}{5500}\cdot100\\\\\frac{1000}{5500}\cdot100 \\\\0.\overline{18} \cdot100\\\\18.\overline{18}[/tex]

Which rounds to 18.18%.

Hope this helped!

Answer:

8

Step-by-step explanation:

total: 28 water attractions

pools: p

game areas: p + 2

water slides: 50% of 28 = 14

14 + p + p + 2 = 28

2p = 12

p = 6

game areas:

p + 2 = 6 + 2 = 8

Answer:

The amount the school pays is £32.40

Step-by-step explanation:

The cost of each pen = 15 pence

The cost of each ruler = 20 pence

The number of pens bought by the school = 150

The number of rulers bought by the school = 90

The cost reduction (discount) on the items bought = 1/5

Therefore, we have;

The total cost of the pens bought by the school = 150 × 15 = 2250 = £22.50

The total cost of the rulers bought by the school = 90 × 20 = 1800 = £18.00

The total cost of the writing materials (rulers and pens) bought by the school = £22.50 + £18.00 = £40.50

The discount = 1/5 total cost reduction = 1/5×£40.50  = $8.10

The amount the school pays = The total cost of the writing materials - The discount

The amount the school pays = £40.50 - $8.10 =  £32.40

The amount the school pays =  £32.40.

Answer:

It should be 490000.0005

Step-by-step explanation:

4.9*10^5+.0005

10^5=100000

4.9*100000=490000

490000+.0005=490000.0005

Answer:

Step-by-step explanation:

[tex]10^{-5}=\frac{1}{10^{5}}=\frac{1}{100,000}=0.00001\\\\[/tex]

4.9* 10^-5 +0.0005 = 4.9 * 0.00001  + 0.0005

                               = 0.000049 + 0.0005

                              =  0.000549

Answer:

Step-by-step explanation:

The figure above is a rectangle

Area of a rectangle = length × width

From the question

The total length of the rectangle = 3x

The total width of the rectangle = 4x + 5

So the area of the figure is

A = 3x( 4x + 5)

Expand

We have the final answer as

Hope this helps you

The missing probability P(A∪B) will be 37/50.

Probability refers to a possibility that deals with the occurrence of random events.

The probability of all the events occurring need to be 1.

Given information;

P(A)= 7/20,

P(B)=3/5,

P(A∩B) =21/100 ,

We need to find the missing probability P(A∪B).

We know that

P(A∪B)= P(A) + P(B) + P(A∩B)

P(A∪B) = 7/20 + 3/5 + 21/100

P (A U B) = 37/50

Therefore, the missing probability P(A∪B) will be 37/50.

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Answer: (-1,-3)

Step-by-step explanation:

midpoint formula [tex]\left(\frac{x_2+x_1}{2},\:\:\frac{y_2+y_1}{2}\right)[/tex]

[tex]\left(x_1,\:y_1\right)=\left(-3,\:-2\right),\:\left(x_2,\:y_2\right)=\left(1,\:-4\right)[/tex]

[tex]\left(\frac{1-3}{2},\:\frac{-4-2}{2}\right)[/tex]

[tex](\frac{-2}{2},\frac{-6}{2})[/tex]

-2/2=-1

-6/2=-3

So the midpoint is (-1,-3)

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Answer:

25,070 gal

Step-by-step explanation:

will make it simple and short.

vol =  ( a + b ) * h/2 times the depth

vol = (8 + 3.5) x (35/2) x 20 = 4025 cu. ft.  ---------->>> then convert to gal.

                              6.2288 gal

vol = 4025 cu.ft. x ----------------- =  25,070 gal

                                 1 cu.ft.

Hi there! Hopefully this helps!

----------------------------------------------------------------------------------------------------------

First we need to substitute the value of the variable into the expression and simplify.

b-(b+a×4c÷4) = 1 - (1 + -6 × 4(2) ÷ 4).

Now we need to solve 1 - (1 + -6 × 4(2) ÷ 4).

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

1 - (1 + -6 × 4(2) ÷ 4)

|

|  First, we cancel out 4 and 4.

\/

1 - (1 - 6 × 2)

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Next, we multiply -6 and 2 to get -12.

1 - (1 - 12)

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Then we subtract 12 from 1 to get -11.

1 - (-11)

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The opposite of -11 is 11.

1 + 11.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Answer:

Answer: 12

Hope this helps

Answer:

D) BAC is the correct answer as A is at the middle.

All of the options describe an angle with a vertex at A.

In geometry, a vertex is a point where two or more lines, curves, or edges meet to form an angle or a corner.

It is the common endpoint of two or more rays, line segments, or sides of a polygon.

We have,

All of the options describe an angle with a vertex at A.

In each option, A is the vertex of the angle.

The letters that come before and after A indicate the other two points that form the angle. So:

∠ABC is an angle with vertex A and points B and C on either side.

∠CAB is an angle with vertex A and points C and B on either side. (Note that the order of the letters is reversed from option A.)

∠ACB is an angle with vertex A and points C and B on either side. (Note that the order of the letters is reversed from option B.)

∠BAC is an angle with vertex A and points B and C on either side. (Note that the letters are in a different order than option A.)

Thus,

All of the options describe an angle with a vertex at A.

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Answer:

3 hours and 27 minutes

Step-by-step explanation:

2:05 pm = 14:05 hours

1 hour = 60 minutes

14:05 = 13 hours + 60 minutes + 5 minutes = 13 hours + 65 minutes

then:

 13h  65m

- 10h  38m

=  3h  27m

they drive:

3 hours and 27 minutes

Answer:

x= 36 km

Step-by-step explanation:

Vince went on a 3 day hiking trip. Each day, he walked 3/4 the distance that he walked the day before. He walked 83.25 kilometers total in the trip. How far did Vince walk on the 1st day of the trip?

Assume vince walked x km on the first day .

The following equation can be formed

x + 3/4 x + (3/4)^2 x = 83.25

x + 0.75x + 0.5625x = 83.25

Add the like terms

2.3125x = 83.25

Divide both sides by 2.3125

x = 36 km.

Answer:

36

Step-by-step explanation:

Answer:

(6⁴ * 8⁻⁷) ⁻⁹

equivalent expressión is:

1 / (6⁴ * 8⁻⁷)⁹

Step-by-step explanation:

(6⁴ * 8⁻⁷) ⁻⁹

= 1 / (6⁴ * 8⁻⁷)⁹