SOLUTION: We are supposed to factor completely. The problem is: 4xcubed plus 12xsquared minus 8x equals I have it factored to 4x(xsquared + 3x - 2) I know it has to factor down to someth

Algebra ->  Distributive-associative-commutative-properties -> SOLUTION: We are supposed to factor completely. The problem is: 4xcubed plus 12xsquared minus 8x equals I have it factored to 4x(xsquared + 3x - 2) I know it has to factor down to someth      Log On


   

Question 51316: We are supposed to factor completely. The problem is:
4xcubed plus 12xsquared minus 8x equals
I have it factored to 4x(xsquared + 3x - 2) I know it has to factor down to something like, 4x(x+ )(x- )I'm stuck..... Any help would so be appreciated! Thank you
Found 2 solutions by checkley71, tutorcecilia:
Answer by checkley71(8403) About Me  (Show Source):
You can put this solution on YOUR website!
4X^3+12X^2+8X=0 OR 4X(X^2+3X+2=0 OR 4X=0 OR X=0 & (X+2)(X+1)=0 OR X+2=0 OR
X=-2 & X+1=0 OR X=-1
PROOF 4*0^3+12*0^2+8*0=0 OR 0+0+0=0 OR 0=0
4(-2)^3+12(-2^2)+8*-2=0 OR 4*-8+12*4-16=0 OR -32+48-16=0 OR 0=0
4(-1)^3+12(-1^2)+8*-1=0 OR 4*-1+12*1-8=0 OR -4+12-8=0 OR 0=0













Answer by tutorcecilia(2152) About Me  (Show Source):
You can put this solution on YOUR website!
4x(x^2 + 3x - 2)[Factor using the quadratic formula]
.
x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
.
x+=+%28-3+%2B-+sqrt%28+3%5E2-%284%29%281%29%28-2%29+%29%29%2F%28%282%29%281%29%29+
.
x+=+%28-3+%2B-+sqrt%28+9%2B8%29+%29%29%2F%28%282%29%29+
.
x+=+%28-3+%2B-+sqrt%28+17%29+%29%29%2F%28%282%29%29+
.
x+=+%28-3+%2B+sqrt%28+17%29+%29%29%2F%28%282%29%29+ = .5615
or
x+=+%28-3+-+sqrt%28+17%29+%29%29%2F%28%282%29%29+ = -3.562
.
So, the "x"'s are"
4x=0 or x=0
x=.5615
x=-3.652
Factoring the equation than gives:
(4x)(x-.5615)(x+3.652)
Multiply the factors out and you should get the original equation.