SOLUTION: {{{ A(x+1)(x+3) + B(x-1)(x+4) + C(x+2)(x+3) = 6x^2 +34x + 46 }}} i need to find the constant values of A B and C ? i tried substituting x=-1 and got: -6B + 2C = 18 (but i

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: {{{ A(x+1)(x+3) + B(x-1)(x+4) + C(x+2)(x+3) = 6x^2 +34x + 46 }}} i need to find the constant values of A B and C ? i tried substituting x=-1 and got: -6B + 2C = 18 (but i      Log On


   

Question 345006:
i need to find the constant values of A B and C ?
i tried substituting x=-1
and got:
-6B + 2C = 18 (but i think thats wrong, and dont know what to do from there)
I also worked out that B=2 substititing x=-3 into the equation but i dont know how to work out A and C, maybe use the coefficient of x^2 but i cant work out how to do that?
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
You have to expand all of the products and get one big equation.
Then match the coefficients of the terms.

A%28x%5E2%2B4x%2B3%29%2BB%28x%5E2%2B3x-4%29%2BC%28x%5E2%2B5x%2B6%29=6x%5E2%2B34x%2B46
%28A%2BB%2BC%29x%5E2%2B%284A%2B3B%2B5C%29x%2B%283A-4B%2B6C%29=6x%5E2%2B34x%2B46
So now you have three equations with three unknowns.
A%2BB%2BC=6
4A%2B3B%2B5C=34
3A-4B%2B6C=46
Solve for A,B,C using substitution, elimination, or matrix methods.
Re-post if you need more help.