Question

Factor 21x^2 - 14x - 56

Answer 1

7((x-2)(3x+4))

Explanation:

Common factor of 7 in this quadratic formula.
`7(3x^2-2x-8)`; -8 * 3x^2 = -24x^2, now find factors of this product that equal to -2x when added. The factors that fit this is -6x and 4x. So, if you make a generic rectangle you can find the product. You get 7((x-2)(3x+4))