Kevin S. answered 10/22/12
Using the commutative property, rearrange terms so they are similarly grouped:
4z + 32 - yz - 8y
Looking at it now, you can factor a 4 out of the first two terms, and a -y out of the last 2
4(z+8) -y(z+8)
Factor (z+8) out of both, and you're left with (z+8)(4-y)
For the second problem, follow the same steps. (Hint: in this one, the terms are similarly grouped, so you can start with finding a factor to pull out)