Answer:
2(x - 5)(x + 4)
Explanation:
Given
- 40 + 2x² - 2x , that is
2x² - 2x - 40 ← factor out 2 from each term
= 2(x² - x - 20) ← factorise the quadratic
Consider the factors of the constant term (- 20) which sum to give the coefficient of the x- term (- 1)
The factors are - 5 and + 4 , since
- 5 × 4 = - 20 and - 5 + 4 = - 1 , then
x² - x - 20 = (x - 5)(x + 4) and
2x² - 2x - 40 = 2(x - 5)(x + 4) ← in factored form