Answer:
x is greater than or = to 8
Answer: Choice B
(-2, 5)
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Explanation:
The original system is
Multiply both sides of the second equation by 3. Doing so leads to this updated system of equations
Now add straight down
The x terms add to -4x+3x = -1x = -x
The y terms add to 3y+(-3y) = 0y = 0
The terms on the right hand sides add to 23+(-21) = 2
We end up with the equation -x = 2 which solves to x = -2
Now use this to find y. You can pick any equation with x,y in it
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-4x+3y = 23
-4(-2)+3y = 23
8+3y = 23
3y = 23-8
3y = 15
y = 15/3
y = 5
Or
x-y = -7
-2-y = -7
-y = -7+2
y = -5
y = 5
Either way, we get the same y value.
So that's why the solution is (x,y) = (-2, 5)
To find it directly
A = 2 pi r h
A is proportional to rh
factor 2
A is multiplied by 2 * 2 = 4
factor 3
3 * 3 =9
factor 5
5 * 5 = 25
factor 10
10 * 10 = 100
(b) the increase in A by factor x is x^2
c(20)^2 = 400
Answer: B( 5 : 15,0)
Step-by-step explanation: Please find the attached file for the solution
Answer:
1. 195=6.50·c
2. 30
Step-by-step explanation:
195=6.5·c
Divide both sides by 6.5
30=c