Answer:
(y - 5)(y + 4)
Step-by-step explanation:
Given
y² - y - 20
Consider the factors of the constant term (- 20) which sum to give the coefficient of the y- term (- 1)
The factors are - 5 and + 4, since
- 5 × 4 = - 20 and - 5 + 4 = - 1, thus
y² - y - 20 = (y - 5)(y + 4) ← in factored form
