Question

Using the X Method to Factor

ax2 + bx + c
If x - 10 is a factor of x2 - 8x - 20, what is the other
factor?
X+

Answer 1

If one factor is (x-10) then the other factor is (x+2).

Explanation:

We need to factorize the term x^2-8x-20

For factorization we need to break the middle term.

Middle term : -8x

Product of first and last term: -20x^2

Factors: -10x, +2x

Solving:

x^2-8x-20

x^2-10x+2x-20

x(x-10)+2(x-10)

(x-10)(x+2)

So, if one factor is (x-10) then other factor is (x+2)