Answer:
y = -16 (x − 3/8)² + 49/4
Explanation:
y = -16x² + 12x + 10
First, factor the leading coefficient from the first two terms.
y = -16 (x² − 3/4 x) + 10
Complete the square. Take half of the b coefficient, square it, then add and subtract the result.
b = -3/4
b/2 = -3/8
(b/2)² = 9/64
y = -16 (x² − 3/4 x + 9/64 − 9/64) + 10
y = -16 (x² − 3/4 x + 9/64) + 9/4 + 10
y = -16 (x − 3/8)² + 49/4