Answer:
(z+8)(z+9)
Explanation:
The first step is to look at the signs. All the signs are positive so we know that the signs in our factored equation will be positive as well. This tells us that we just need to find what factors of 72 can add up to 17. So, we can get 72 with 36 times 2, 24 times 3, 18 times 4, 12 times 6, and 8 times 9. 36 + 2 does not equal 17, 24 + 3 does not equal 17, 18 + 4 does not, 12 + 6 does not, and 8 + 9 does! So since 8+9=17, we can plug those in. So we take our normal factor form (a variable + or - a number)(a variable + or - a number). Our variable is z, and our signs are positive, and our numbers are 8 and 9. To check use FOIL (multiply the First, Outer, Inner, then Last terms and combine like terms to see if you get your original problem.