Answer:
- 5(x - 4)(x + 4)
Step-by-step explanation:
Given
- 5x² + 80 ← factor out - 5 from each term
= - 5(x² - 16) ← x² - 16 is a difference of squares and factors in general as
a² - b² = (a - b)(a + b), thus
x² - 16 = x² - 4² = (x - 4)(x + 4)
Thus
- 5x² + 80 = - 5(x - 4)(x + 4) ← in factored form
