SOLUTION: how do i solve... directions: write a quadratic equation with the given roots. Write the equation in the form of ax^2+ bx + c = 0, where a, b, and c are integers 1, 4 -2,-5

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equation Customizable Word Problems -> SOLUTION: how do i solve... directions: write a quadratic equation with the given roots. Write the equation in the form of ax^2+ bx + c = 0, where a, b, and c are integers 1, 4 -2,-5       Log On


   



Question 392538: how do i solve...
directions: write a quadratic equation with the given roots. Write the equation in the form of ax^2+ bx + c = 0, where a, b, and c are integers
1, 4
-2,-5
-1/3, -3
if you can help me...can u show me how to do the work so that i can see the process

Found 2 solutions by Alan3354, richard1234:
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
write a quadratic equation with the given roots. Write the equation in the form of ax^2+ bx + c = 0, where a, b, and c are integers
1, 4
-2,-5
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I'll do this one, the others are simpler.
-1/3, -3
If the roots are a and b, the equation is (x-1)*(x-b) = 0
%28x+%2B+1%2F3%29%2A%28x+%2B+3%29+=+0
x%5E2+%2B+%2810%2F3%29x+%2B+1+=+0
3x%5E2+%2B+10x+%2B+3+=+0

Answer by richard1234(7193) About Me  (Show Source):
You can put this solution on YOUR website!
There's a well-known property that says that if r is a root of a polynomial, then x-r is a factor of it. Using this, we see that if 1 and 4 are the roots, then the polynomial is %28x-1%29%28x-4%29 in factored form (there can't be additional factors since we're given it's quadratic). Expanding, we get x%5E2+-+5x+%2B+4.

Use the same process to do the other two.