Answer:
y = x² - 2x - 8
Step-by-step explanation:
Given
y = (x - 4)(x + 2)
Each term in the second factor is multiplied by each term in the first factor, that is
x(x + 2) - 4(x + 2) ← distribute parenthesis
= x² + 2x - 4x - 8 ← collect like terms
= x² - 2x - 8 ← in standard form
