Question

Rewrite the expression as a product of four linear factors:

(12x² – 19x)² – 13(12x² – 19x) – 90

Answer 1

(4x - 9)(3x + 2)(4x - 5)(3x - 1).

Explanation:

Let's substitute y = (12x² - 19x):

So we have y² - 13y - 90, which can be factored as:

y² - 13y - 90 = (y - 18)(y + 5)

Substituting y back:

(12x² - 19x)² - 13(12x² - 19x) - 90 = [(12x² - 19x) - 18][(12x² - 19x) + 5]

= (12x² - 19x - 18)(12x² - 19x + 5)

= (4x - 9)(3x + 2)(4x - 5)(3x - 1)