GED Math: Basic Algebra

Question

Factor the following polynomial?

7x³ - 63x

Answer 1

Original expression:

7x³ - 63x

Each term has a common factor of 7x. Factor 7x from each term:

7x³ - 63x → (7*x*x*x - 7*9*→x) →7x (x² - 9)

Both terms inside the parentheses are perfect squares, so one binomial is addition and the other is subtraction:

7x (x + ?)(x - ?)

Determine the square root of 9. The will be the second term in each binomial:

√9 → √3*3 = 3

Now put it all together:

7x (x + 3)(x - 3)