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Polynomials HELP (1 Viewer)

foram

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Solve the equation 10x^3 + 23x^2 + 5x - 2 = 0 given that one root is four times a second root.

I tried to use the relationship between roots and coefficients and I ended up with:

Let the roots equal A , 4A , B

-b/a = 5A + B = -23/10

c/a = 4A^2 + 5AB = 1/2

-d/a = 4BA^2

Then I tried to find A and B, but i'm not getting anywhere...

Can anybody explain to me what i'm doing wrong, and how to solve this question please?
 

mantiswhoprays

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i got the answer a different way, but it still worked. did it specify that you had to use the root coefficient rule?
 

foram

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thankyou so much :D. i assumed i was supposed to use the relation between coefficients and roots, because the question seemed to place to much emphasis on the roots :D. I guess i needed to think of it in a different way.

thankyou again.
 

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