Answer:
(k+8)(k+9)
Explanation:

You are given this equation and asked to factor.
Since the leading coefficient (coefficient of the term with the highest degree) is 1, the factors are (k+_)(k+_).
To find what goes in the __s, find what two numbers multiply to the last term (72) and add to the middle term (17). These two numbers are 8 and 9.
Therefore, the factors are (k+8) and (k+9).
You can check this by multiplying these factors out. (FOIL)

It multiplies to the original expression, so it is correct.