Step-by-step explanation:
7x-21 = 5x +15
7x-5x = 15 + 21
2x = 36
x = 36/2
x = 18
Answer:
x=18
Step-by-step explanation:
Distribute 7 through the parentheses
7x-21=5(x+3)
Move the variable to the left -hand side and change its sign
7x-21-5x=15
Collect like terms
2x=15+21
divide both sides of the equation by 2
x=18
Reflect (-3, 4) across the y-axis. Then reflect the result across the x-axis.
f(x)=3x-3
g(x) 3x^3+5
Find F(-3) and g(-2)
Answer:
f(-3) = -12
g(-2) = -19
General Formulas and Concepts:
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightAlgebra I
FunctionsFunction NotationStep-by-step explanation:
Step 1: Define
Identify
f(x) = 3x - 3
g(x) = 3x³ + 5
f(-3) is x = -3 for function f(x)
g(-2) is x = -2 for function g(x)
Step 2: Evaluate
f(-3)
Substitute in x [Function f(x)]: f(-3) = 3(-3) - 3Multiply: f(-3) = -9 - 3Subtract: f(-3) = -12g(-2)
Substitute in x [Function g(x)]: g(-2) = 3(-2)³ + 5Exponents: g(-2) = 3(-8) + 5Multiply: g(-2) = -24 + 5Add: g(-2) = -19Answer:
f(-3) = -12
g(-2) = -19
Step-by-step explanation:
1.
f(x) = 3x - 3
One is asked to find (f(-3)), substitute (-3) into the given function (f) in place of (-3), and solve to evaluate,
f(-3) = 3(-3) - 3
Simplify,
= -9 - 3
= -12
2.
g(x) = [tex]3x^3+5[/tex]
The problem asks one to find (g(-2)), subtitute (-2) into the function in place of (x) and solve to find tis value,
g(-2) = [tex]3(-2)^3+5\\[/tex]
Remember any number raised to an exponent is equal to the base (the number that is being raised to the exponent) times itself the number of times that the exponent indicates,
[tex]=3(-8)+5\\=-24+5\\=-19[/tex]
A table represents the possibility of an association between eye color and hair color. Hair Color Eye Color Brown Black Green 22 15 Blue 18 19 In order to determine if there is a significant difference between eye color and hair color, the chi-square test for association and independence should be performed. What is the expected frequency of Blue Eyes and Black Hair?
Answer:
17
Step-by-step explanation:
_____________ Hair color
Eye color ___ Brown ___ Black ___ total
Green _____ 22 ________ 15 ____ 37
Blue _______ 18 ________ 19 ____ 37
Total _______40 ________34 ____ 74
Calculate the expected frequency of Blue Eyes and Black Hair?
The expected frequency Count ;
(row total * column total) / total number of observations
Expected frequency ;
Blue eye n black hair = (37 * 34) / 74
Expected frequency count = 1258 / 74 = 17
Expected count = 17
Answer:
The row total of blue eyes is 18 + 19 = 37.
The column total of black hair is 15 + 19 = 34.
The total of the whole table is 22 + 15 + 18 +19 = 74.
Step-by-step explanation:
E=(37)(34)/74=1258/74=17
Please help ,cant figure it out.
Answer:
B. √2^5
Step-by-step explanation:
(2^½. 2^¾)²
= 2¹ . 2^(1½)
= 2^(2½)
= 2^(5/2)
=√2^5
Polygon ABCD, shown in the figure, is dilated by a scale factor of 8 with the origin as the center of dilation, resulting in the image ABCD.
The slope of 'D'is
Reset
Next
Il rights reserved.
Properties of Dilati...
DELL
Answer:
(D) is equal to 8 so that means that u have to divide and multiply all in one
Answer:
Reflection
Step-by-step explanation:
Need help finding the factor of 2y^2-2y-4
Answer:
hope it helps you............
Answer:
2(y - 2)(y + 1)
Step-by-step explanation:
Given
2y² - 2y - 4 ← factor out 2 from each term
= 2(y² - y - 2) ← factor the quadratic
Consider the factors of the constant term (- 2) which sum to give the coefficient of the y- term (- 1)
The factors are - 2 and + 1, since
- 2 × 1 = - 2 and - 2 + 1 = - 1 , then
y² - y - 2 = (y - 2)(y + 1)
Then
2y² - 2y - 4 = 2(y - 2)(y + 1) ← in factored form
Kin travels 440 miles by train at an average speed of 110 mph.
Ayaan flies the same distance at an average speed of 880 mph.
Find the difference between their travel times.
Give your answer in hours.
Answer:
3 1/2 hours
Step-by-step explanation:
time = distance/speed
440/110 = 4 hours
440/880 = 1/2 hours
4 minus 1/2 is 3 1/2
Answer:
hi
Step-by-step explanation:
i just need some points sorry not sorry
Find the missing length indicated
x = 65
Step-by-step explanation:
cos theta = 25/x
cos theta = x/169
25/x = x/169
x² = 169 x 25
x = 65
The missing length x = 65, using the Pythagoras Theorem.
What is the Pythagoras Theorem?
According to the Pythagoras Theorem, in a right triangle, the square of the hypotenuse is equal to the sum of the squares of the legs.
How to solve the question?In the question, we are asked to find the value of x.
In the right triangle ABC, by Pythagoras' Theorem,
AC² + BC² = AB²,
or, x² + BC² = (144 + 25)²,
or, BC² = 169² - x² ... (i).
In the right triangle ACD, by Pythagoras Theorem,
AD² + DC² = AC²,
or, 25² + DC² = x²,
or, DC² = x² - 25² ... (ii).
In the right triangle BCD, by Pythagoras Theorem,
BD² + DC² = BC²,
or, 144² + x² - 25² = 169² - x² {Substituting BC² = 169² - x² from (i) and DC² = x² - 25² from (ii)},
or, x² + x² = 169² + 25² - 144² {Rearranging},
or, 2x² = 28561 + 625 - 20736,
or, 2x² = 8450,
or, x² = 4225,
or, x = √4225 = 65.
Thus, the missing length x = 65, using the Pythagoras Theorem.
Learn more about the Pythagoras Theorem at
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Lance is selling T-shirts for $10 each and hats for $12.50 each. He wants to earn at least $400 per week to cover his expenses. Which graph best represents the number of T-shirts and hats Lance should sell to meet his goal?
Answer:
Step-by-step explanation:
4 7/8 - 2 3/8 simplest form
Answer:
2 1/2
Step-by-step explanation:
4 7/8= 39/8
2 2/8= 19/8
39/8 - 19/8 = 20/8 = 2 4/8 = 2 1/2
Determine which value best approximates the length of the arc represented by the integral ∫_0^1 √1 + [d/dx(4/x+1)]² dx.
(Make your selection on the basis of a sketch of the arc and not
by performing any calculations.)
(a) 10
(b) -5
(c) 2
(d) 4
(e) 1
Answer:
Option C
Step-by-step explanation:
From the question we are told that:
Length of arc integral
[tex]l=\int_0^1 \sqrt{1 + [\frac{d}{dx}(\frac{4}{x+1})]^2 dx}[/tex]
The Sketch is attached below
From the Graph
Approximation gives length of arc as
[tex]l=\sqrt{5}[/tex]
[tex]l=2[/tex]
Option C
Fran swims at a speed of 2.1 km/h in still water. The Lazy River flows at a speed of 0.7 km/h. How long will it take Fran to swim 10 km upstream?
What is Fran's speed while swimming upstream?
Answer: Fran's speed while swimming upstream = 1.4 km/h
Step-by-step explanation:
Given: Fran's swimming speed = 2.1 km/h
Speed of river = 0.7 km/h
The direction against the stream is called upstream.
Speed in Upstream = Fran's swimming speed - Speed of river
= 2.1-0.7 km/h
= 1.4 km/h
hence, Fran's speed while swimming upstream = 1.4 km/h
Find the distance between the pair of points: (0,1) and (1,0)
Answer:
sqrt(1^2 + 2^2)
[tex]\sqrt{2}[/tex]
Step-by-step explanation:
Mass of a proton: 1.007825 units
Mass of a neutron: 1.008665 units
Calculate the mass Defect of 214 N has actual mass of 14.0031 u.
Given:-
mass of proton = 1.007825 umass of neuron = 2.008625 u .Actual mass = 14.0031 uTo find:-
The mass defect.Answer:-
Mass defect arises when the mass of the atom differs from the sum of masses of nucleons . As we know that the nucleus of an atom is made up of neutrons(n) and protons (p) , and the total mass of a atom is the mass of nucleons ( protons and neutrons ) as electrons have mass very low as compared to that of n or p .
If we denote mass number by [tex]\green{A}[/tex] , then ;
[tex]\implies A = n_{\rm neutrons} + n_{\rm protons} [/tex]
Let [tex] Z[/tex] be the atomic number, then ;
[tex]\implies n_p = Z [/tex]
So, the number of neutrons will be;
[tex]\implies n_n = (A-Z) [/tex]
Therefore total mass would be ;
[tex]\implies M = m_pZ +m_n (A-Z) [/tex]
Then the mass defect would be ,
[tex]\implies\underline{\underline{\green{ \Delta M = [Zm_p + (A-Z)m_n - M ] }}} [/tex]
where ,
[tex]Z [/tex] = atomic number[tex] A[/tex] = mass number[tex] m_p [/tex] = mass of a proton[tex] m_n [/tex] = mass of a neutron_______________________________________
Now we know that the Atomic number of Nitrogen is 7(Z) and its mass number is 14(A) .
Now substitute the respective values,
[tex]\implies \Delta M = 7(1.007825) + (14-7)1.008665 - 14.0031 \\ [/tex]
[tex]\implies \Delta M = 7.054775 + 7(1.008665) - 14.00 31 [/tex]
[tex]\implies \Delta M = 7.054775 + 7.060655 - 14.0031 [/tex]
[tex]\implies \Delta M = 14.11543 - 14.0031 [/tex]
[tex]\implies \underline{\underline{\green{ \Delta M = 0.11233 \ u }}}[/tex]
Hence the mass defect is 0.11233 u .
Also this mass defect appears as energy which is responsible for the binding of nucleons together.
and we are done!
What is the tens digit in the sum 7! + 8! + 9! + … + 2006!
You can get the tens digit of any number n by computing the quotient
(n (mod 100)) / 10
and ignoring the remainder.
Taking the given sum (mod 100) gives
7! + 8! + … + 2006! ≡ 7! + 8! + 9! (mod 100)
since the last 1997 terms (i.e. 10! up to 2006!) in the sum are multiples of 100. That is,
• every term beyond 100! is obviously a multiple of 100
• every term beyond 25! contains a factor of both 4 and 25
• every term beyond 10! contains two factors each of both 2 and 5 (i.e. every factorial term contains 4, 5, and 10)
The remaining sum is easy to compute by hand:
7! + 8! + 9! = 7! (1 + 8 + 8 × 9) = 5040 × 81 = 408,240
so the tens digit is 4.
PLEASE HELP WILL MARK BRANIEST
Answer:
1.14male studying biology
Let r be the binomial random variable corresponding to the number of people that will live beyond their 90th birthday,
r ≥ 15.
We want to find
P(r ≥ 15)
using the normal approximation given 625 trials and a probability of a 4.4% success on a single trial.
Answer:
P(r ≥ 15) = 0.9943.
Step-by-step explanation:
We use the normal approximation to the binomial to solve this question.
Binomial probability distribution
Probability of exactly x successes on n repeated trials, with p probability.
Can be approximated to a normal distribution, using the expected value and the standard deviation.
The expected value of the binomial distribution is:
[tex]E(X) = np[/tex]
The standard deviation of the binomial distribution is:
[tex]\sqrt{V(X)} = \sqrt{np(1-p)}[/tex]
Normal probability distribution
Problems of normally distributed distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
When we are approximating a binomial distribution to a normal one, we have that [tex]\mu = E(X)[/tex], [tex]\sigma = \sqrt{V(X)}[/tex].
625 trials and a probability of a 4.4% success on a single trial.
This means that [tex]n = 625, p = 0.044[/tex]
Mean and standard deviation:
[tex]mu = E(X) = np = 625*0.044 = 27.5[/tex]
[tex]\sigma = \sqrt{V(X)} = \sqrt{np(1-p)} = \sqrt{625*0.044*0.956} = 5.13[/tex]
P(r ≥ 15)
Using continuity correction, this is [tex]P(r \geq 15 - 0.5) = P(r \geq 14.5)[/tex], which is 1 subtracted by the p-value of Z when X = 14.5. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{14.5 - 27.5}{5.13}[/tex]
[tex]Z = -2.53[/tex]
[tex]Z = -2.53[/tex] has a p-value of 0.0057
1 - 0.0057 = 0.9943
So
P(r ≥ 15) = 0.9943.
For this question I am sure the answer is 81% as you divide 45 and 55. However, it is stating my answer is incorrect even though I put 0.81% as well. Did I round wrong or is the answer wrong completely?
Answer:
it says round to the nearest 10th so it wouldn't be 81, it would be 81.8%
A tank contains 1000L of pure water. Brine that contains 0.04kg of salt per liter enters the tank at a rate of 5L/min. Also, brine that contains 0.06kg of salt per liter enters the tank at a rate of 10L/min. The solution is kept thoroughly mixed and drains from the tank at a rate of 15L/min.
1. How much salt is in the tank after t minutes?
2. How much salt is in the tank after 60 minutes?
Answer:
1) x = [ - (12/1000)* e∧ ( - 15/1000)*t + 12/1000 ] /e∧ - (15/1000)*t
2) x = - 0,012 * ( e ∧ 0.18 + 0,012 ) / e∧-0,18
Step-by-step explanation:
1.-Quantity of salt in the tank after t minutes
The rate of change of the quantity of salt in the tank is:
dx(t) /dt = original quantity (0) + input quantity - output quantity (1)
quantity = concentration* rate Then
input quantity = 0.04 Kg/lt * 5 Lt/min + 0.06 Kg/lt * 10Lt/min = 0.2 Kg/min
+ 0.6 Kg/min = 0,8 Kg/lt
output quantity = Output concentration * rate of draining
rate of draining = 15 Lt/min
The input quantity and the output quantity occur at the same rate therefore the volume in the tank is constant 1000Lt.
output quantity = (x/1000 )*15
Plugging these values in equation (1) we get.
dx/dt = 0,8 - ( x/1000)* 15
The last one is a differential first-order equation like
x´ + P(t)*x = q(t)
and the solution is:
x*μ = ∫ q(t)*μ*dt + C
where μ is the integration factor e ∧ ∫p(t)*dt
let´s call b = -15/1000
μ = e ∧ ∫p(t)*dt = e∧∫ b*dt = e∧ b*t = e∧ ( -15/1000)*t
μ = e∧ - (15/1000)*t
Then x*μ = x * e∧ - (15/1000)*t
∫ q(t)*μ*dt = ∫ 0.8 * e∧ - (15/1000)*t*dt = 0.8 * ∫ e∧bt * dt
∫ q(t)*μ*dt = 0.8 * ( 1/b ) e∧bt = - 0,8 *( 15/1000) * e∧ ( - 15/1000)*t
∫ q(t)*μ*dt = - (12/1000)* e∧ ( - 15/1000)*t
x * e∧ - (15/1000)*t = - (12/1000)* e∧ ( - 15/1000)*t + C
Initial condition t = 0 x = 0
0 = - (12 / 1000 )* e⁰ = C
C = 12/1000
x * e∧ - (15/1000)*t = - (12/1000)* e∧ ( - 15/1000)*t + 12/1000
x = [ - (12/1000)* e∧ ( - 15/1000)*t + 12/1000 ] /e∧ - (15/1000)*t
When t = 60 min
x = [ - (12/1000)* e∧ ( - 15/1000)*12 + 12/1000 ] / e∧ - (15/1000) * 12
x = - 0,012 * ( e ∧ 0.18 + 0,012 ) / e∧-0,18
What is the value of angle v?
Answer:
x = 5
Step-by-step explanation:
a) The third interior angle of this triangle is 180 - 20 x.
The three interior angles must sum up to 180 degrees.
Therefore, 60 + 7x + 5 + 180 - 20x = 180, or
65 + 180 - 13x = 180, or
65 - 13x = 0
Finally, 13x = 65, and so x = 5
please help meeeeeeee
pt 4
Answer:
The answer is
[tex]2 {x}^{2} + 3x - 1 = 0[/tex]
Why? Below I explain
Step-by-step explanation:
That formula has three variables a, b and c.
So, a = 2, b = 3 and c = -1
Because the formula is written like
[tex] \frac{ - b + - \sqrt{ {b}^{2} - 4 \times a \times c} }{2 \times a} [/tex]
Rectangle ABCD translates 4 units down and 2 units to the right to form rectangle A'B'C'D'. The vertices of rectangle ABCD are labeled in alphabetical order going clockwise around the figure. If AB = 3 units and AD = 5 units, what is the length of B'C'?
Answer:
The length of BC is 14 units.Step-by-step explanation:
[tex]hope \: \: it \: \: helps} \beta \alpha \infty [/tex]
The length of B'C' is 0 units.
What is translation?It is the movement of the shape in left, right, up, and down direction.
The translated shape will have the same shape and shape.
There is a positive value when translated to the right and up.
There is a negative value when translated to the left and down.
We have,
The length of AD = 5 units.
Since the rectangle translates down by 4 units,
The length of A'D' =5 units.
The width of the original rectangle is AB, which is 3 units.
Since the rectangle translates to the right by 2 units,
The width of the new rectangle = 3 units.
Now,
The length of B'C' is the same as the length of AD', which is 5 units.
Subtracting 5 units from 5 units gives us a length of 0 units.
Thus,
The length of B'C' is 0 units.
Learn more about translation here:
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Which of the following coordinates exists on the line y = 2x + 4?
A. (2, 4)
B. (1, 5)
C. (-3, -2)
D. (-1, 3)
How do you find the surface area
Answer:
It depends on what shape you have. Here are some formulas for different shapes.
Step-by-step explanation:
Rectangular prism: 2lw + 2lh + 2wh
Cylinder: 2 pi r² + 2 pi rh
Sphere: 4 pi r²
Cone: pi r² + pi rl
Square-based pyrimid: 1/2lp +B
I hope this helps!
Determine the measure of
CD
from the diagram below.
Answer:
m(arc CD) = 112°
Step-by-step explanation:
Use the property of intersecting chords and angles between these chords,
m∠CED = [tex]\frac{1}{2}(\text{arc CD}+\text{arc}AB)[/tex]
m∠CED + m∠AED = 180°
80° + m∠CED = 180°
m∠CED = 100°
Now substitute the measure of angle CED and arc AB in the expression,
100° = [tex]\frac{1}{2}(88^{\circ}+\text{arc CD})[/tex]
200° = 88° + m(arc CD)
m(arc CD) = 112°
A plane left Kennedy airport on Tuesday morning for an 630mile 5 hour trip for the first part of the trip the average speed was 120 mph for the remainder of the trip the average speed was 130 mph how long did the plane fly at each speed
Answer:
The plane travelled for [tex]\text{$2$ hours}[/tex] at an average of speed [tex]120\; \rm mph[/tex] and [tex]\text{$3$ hours}[/tex] at an average speed of [tex]130\; \rm mph[/tex].
Step-by-step explanation:
Let [tex]x[/tex] denote the number of hours that the plane travelled at an average speed of [tex]120\; \rm mph[/tex].
Given that the trip is [tex]5\; \text{hours}[/tex] long in total, the plane would have travelled at an average speed of [tex]130\; \rm mph[/tex] for [tex](5 - x)\; \text{hours}[/tex].
The plane would have travelled [tex]120\, x[/tex] miles after [tex]x\; \text{hours}[/tex] at an average speed of [tex]120\; \rm mph[/tex]. Likewise, the plane would have travelled [tex]130\, (5 - x)\; \text{miles}[/tex] after [tex](5 - x)\; \text{hours}[/tex] at an average of [tex]130\; \text{mph}[/tex].
The plane has travelled [tex]630\; \text{miles}[/tex] in total. In other words:
[tex]120\, x + 130\, (5 - x) = 630[/tex].
Solve this equation for [tex]x[/tex]: [tex]x = 2[/tex].
In other words, the plane has travelled for [tex]\text{$2$ hours}[/tex] at an average of speed [tex]120\; \text{mph}[/tex]. It would have travelled for [tex](5 - x)\; \text{hours} = (5 - 2)\; \text{hours} = 3 \; \text{hours}[/tex] for the other part of the trip (at an average speed of [tex]130\; \text{mph}[/tex].)
simplify into one fraction 8x/x-8 - 2/x-8
Answer:
- 2+8x/x
Step-by-step explanation:
See image below:)
FYI you can use the app photo math you just take a pic of the problem and it gives you the answer and explains the steps and it is free
Answer:
(8x-2) / (x-8)
Step-by-step explanation:
8x/x-8 - 2/x-8
Since the denominator is the same, we can add the numerators
(8x-2) / (x-8)
Please help will mark BRAINLIEST!!!
Answer:
b, c, a
Step-by-step explanation:
In a triangle, the largest angle is opposite the longest side. The smallest angle is opposite the shortest side.
This triangle has 2 given angles, 50° and 60°.
We can find the measure of the third angle, x.
50 + 60 + x = 180
x + 110 = 180
x = 70
The three angles have measures 50°, 60°, and 70°.
The shortest side is opposite the smallest angle. That is side a.
The longest side is opposite the largest angle. That is side b.
The order from longest to shortest is
b, c, a
Alec bakes spherical rolls of bread. Each roll is about 8cm
wide. What is the approximate volume of each roll? Use
3.14 to approximate a.
Answer:
Step-by-step explanation:
2143.57
Find the value of x° in rhombus ABCD.