SOLUTION: Factor completely, 11x(4x-3)-6(4x-3)= 2x(x-5)-(x-5) 3x^3-4x^2+6x-8= xy+2x-y-2= 2x^2+2x-24=

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: Factor completely, 11x(4x-3)-6(4x-3)= 2x(x-5)-(x-5) 3x^3-4x^2+6x-8= xy+2x-y-2= 2x^2+2x-24=      Log On


   



Question 535799: Factor completely,
11x(4x-3)-6(4x-3)=
2x(x-5)-(x-5)
3x^3-4x^2+6x-8=
xy+2x-y-2=
2x^2+2x-24=

Answer by KMST(5328) About Me  (Show Source):
You can put this solution on YOUR website!
11x%284x-3%29-6%284x-3%29 has a common factor, present in both terms. Getting that common factor out is applying the distributive property backwards, like this
11x%284x-3%29-6%284x-3%29=%2811x-6%29%284x-3%29
2x%28x-5%29-%28x-5%29 Same thing here
2x%28x-5%29-%28x-5%29=2x%28x-5%29-1%2A%28x-5%29=%282x-1%29%28x-5%29
3x%5E3-4x%5E2%2B6x-8 This polynomial is best factored by grouping. There are four terms. Look for a factor common to two of those terms, like 3x
and a factor common to the other two terms. If the polynomial was an exercise in factoring, it should work. (just don't expect it to work for every polynomial.
3x%5E3-4x%5E2%2B6x-8=%283x%5E3%2B6x%29-%284x%5E2%2B8%29=3x%28x%5E2%2B2%29-4%28x%5E2%2B2%29
Do you see now another common factor? Keep factoring.
3x%28x%5E2%2B2%29-4%28x%5E2%2B2%29=%283x-4%29%28x%5E2%2B2%29 and that's your polynomial fully factored.
xy%2B2x-y-2 is another 4-term factor-by-grouping problem. By the way, there are two ways to group. They both work (unless you make a mistake). You may see only one way, but that would be enough.
xy%2B2x-y-2=%28xy-y%29%2B%282x-2%29=y%28x-1%29%2B2%28x-1%29=%28y%2B2%29%28x-1%29+
2x%5E2%2B2x-24is a tougher factoring problem. If it can ve facored with nice integer numbers, it's going to end up being
2x%5E2%2B2x-24=%282x%2Ba%29%28x%2Bb%29 with a%2Ab=-24
That gives you a bunch of choices for a and b because there are several pairs if factors whose products yield 24, and then you have a choice of which one to give the minus sign to. You know that the product term in x is
2bx%2Bax=%282b%2Ba%29x=2x, so 2b%2Ba=2
I would try pairs like 3 and 8 (3x8=24) or 4 and 6 (4x6=24) rather than 2 and 12 or 1 and 24, because you need to add to 2, which is a small number.
Trying 8 and -3: 2x8-3=13 does not work,
but 2x(-3)+8=2 does. Lucky first guess!
Let's verify
%282x%2B8%29%28x-3%29=2x%5E2-6x%2B8x-24=2x%5E2%2B2x-24 We got it!