SOLUTION: Find the roots of the equation 40x-80=5x^2 by Factoring..

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Question 563073: Find the roots of the equation 40x-80=5x^2 by Factoring..
Found 2 solutions by nerdybill, Maths68:
Answer by nerdybill(7384) About Me  (Show Source):
You can put this solution on YOUR website!
40x-80=5x^2
-80=5x^2-40x
0=5x^2-40x+80
divide both sides by 5:
0=x^2-8x+16
0 = (x-4)(x-4)
x = 4

Answer by Maths68(1474) About Me  (Show Source):
You can put this solution on YOUR website!
40x-80=5x%5E2
5%288x-16%29=5x%5E2
Divide by 5 both sides of above equation
5%288x-16%29%2F5=5x%5E2%2F5
cross%285%29%288x-16%29%2Fcross%285%29=cross%285%29x%5E2%2Fcross%285%29
8x-16=x%5E2
x%5E2-8x%2B16=0
x%5E2-4x-4x%2B16=0
x%28x-4%29-4%28x-4%29=0
%28x-4%29%28x-4%29=0%29
%28x-4%29=0+or+%28x-4%29=0%29
x-4=0%29
x=4

Check
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40x-80=5x%5E2
Put x=4
40%284%29-80=5%284%29%5E2
160-80=5%2816%29
80=80