Answer:
b² +12b +32 = (b+4)(b+8)
Explanation:
The product of binomial factors (x+a) and (x+b) is ...
(x+a)(x+b) = x² +ax +bx +ab
= x² + (a+b)x + ab
That is, the coefficient of x is the sum of factors of the constant term.
In order to determine "a" and "b", you can look at the factors of 32 and see which pair has a sum that is 12.
32 = 1×32 = 2×16 = 4×8
The last factor pair has a sum that is 12, so your factorization can be
b² +12b +32 = (b+4)(b+8)