Answer:
(9 + b)(7 - b)
Step-by-step explanation:
Factoring by the difference of squares method, that is
a² - b² = (a + b)(a - b)
Note that 64 - (b + 1)² ← is a difference of squares, that is
64 - (b + 1)² = 8² - (b + 1)²
with a = 8 and b = b + 1, hence
64 - (a + b)² = (8 + b + 1)(8 - (b + 1)) = (9 + b)(7 - b)
