Answer:
(2 + r)(16 + r)
Explanation:
Consider the factors of the constant term (32) which sum to give the coefficient of the r- term (+ 18)
The factors are + 16 and + 2
Use these factors to split the middle term
32 + 16r + 2r + r² ( factor the first/second and third/fourth terms by grouping )
= 16(2 +r) + r(2 + r) ← factor out (2 + r)
= (2 + r)(16 + r) ← in factored form