SOLUTION: If 1 and 3 are the roots of x^3+3x^2+mx+n=0. Find the values of m and n.

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Question 796247: If 1 and 3 are the roots of x^3+3x^2+mx+n=0. Find the values of m and n.
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
If 1 and 3 are the roots of x^3+3x^2+mx+n=0.
:
roots of 1 and 3 give factors of
(x-1)(x-3)
FOIL
x^2 -4x + 3
Find the 3rd factor to give the given equation
...x^2 - 4x + 3
.... X .(x + 7)
--------------
......7x^2 - 28x + 21
x^3 - 4x^2 + 3x
-----------------------
x^3 + 3x^2 - 25x + 21
m = -25
n = 21