Answer:
a = -20
h = 6
k = 720
Explanation:
-20x² + 240x = -20(x² - 12x)
- Divide the coefficient of x by 2. 12 ÷ 2 = 6
- Find the square of 6. 6² = 36.
- Add and subtract 36 to balance the expression.
= -20 (x² - 12x + 6² - 6²)
= -20*(x² - 12x + 36 - 36)
= -20* (x² - 12 + 36) - 36 *(-20)
- Compare x² - 12x + 36 with identity (a - b)² = a² -2ab +b²
= -20(x - 6)² + 720
a = -20
h = 6
k = 720