Answer:
y = - 1 , y = 17
Explanation:
y² - 16y + 64 = 81 ← y² - 16y + 64 is a perfect square
)y - 8)² = 81 ( take the square root of both sides )
y - 8 = ± = ± 9 ( add 8 to both sides )
y = 8 ± 9
then
y = 8 - 9 = - 1
x = 8 + 9 = 17
8.2m questions
10.9m answers