How do you factor completely: 2x^2 - 6x - 562x26x56?

1 Answer
Jul 18, 2015

Separate out the scalar factor 22 then find pair of numbers 44 and 77 whose product is 2828 and difference 33, hence...

2x^2-6x-56 = 2(x-7)(x+4)2x26x56=2(x7)(x+4)

Explanation:

2x^2-6x-56 = 2(x^2-3x-28)2x26x56=2(x23x28)

To factor x^2-3x-28x23x28, find a pair of numbers whose product is 2828 and whose difference is 33. The pair 77, 44 works.

So x^2-3x-28 = (x-7)(x+4)x23x28=(x7)(x+4)

and

2x^2-6x-56 = 2(x-7)(x+4)2x26x56=2(x7)(x+4)