Question

Re-write the quadratic function below in Standard Form
y= –2(x + 5)(x – 4)

Answer 1

y = - 2x² - 2x + 40

Explanation:

Standard form of a quadratic is y = ax² + bx + c : a ≠ 0

Given

y = - 2(x + 5)(x - 4) ← expand factors using FOIL

= - 2(x² - 4x + 5x - 20)

= - 2(x² + x - 20) ← distribute parenthesis by - 2

= - 2x² - 2x + 40 ← in standard form