SOLUTION: Dear Ma'am/ Sir, Please help me in solving this equation, what are the steps that I should do? Thank you very much for helping me. Here is the question: Find the quadratic equ

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Question 767787: Dear Ma'am/ Sir,
Please help me in solving this equation, what are the steps that I should do? Thank you very much for helping me. Here is the question: Find the quadratic equation whose roots are twice the roots of 4x^2+8x-5=0.
Thanks Again!
Found 2 solutions by tommyt3rd, reviewermath:
Answer by tommyt3rd(5050) (Show Source):
You can put this solution on YOUR website!
ax^2+bx+c
4x^2+8x-5=0
since a*c=-20
we use 10 and -2 as follows

4x^2+10x-2x-5=0
2x(2x+5)-1(2x+5)=0
(2x-1)(2x+5)=0
so x=1/2 or x=-5/2
and so
(x-1)(x+5)=0
x^2-6x-5=0

:)

Answer by reviewermath(1029) (Show Source):
You can put this solution on YOUR website!
Q:
Find the quadratic equation whose roots are twice the roots of
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In , the sum of the roots is and the product of the roots is .
Let r and s be the roots of .
So the sum of the roots is r + s = = -2 and the product of the roots is rs = .
2r + 2s = 2(r + s) = 2(-2) = -4
(2r)(2s) = 4(rs) = = -5
The new quadratic equation is:
- (sum of roots)x + (product of roots) = 0
Answer: