Exercise 9 Page 7

The key phrase is ... increased by ... This indicates that we should add two terms. The two terms that we are adding together are $n$ cubed and $5.$ Since $n$ cubed comes first in the verbal expression, it should be on the left-hand side of the addition. Notice that when something is cubed it is raised to the third power. Note that this is only one of multiple ways to algebraically express the given verbal expression.