#### Explanation:

The formula for total income is:

$T = b + r \cdot s$ where $T$ is the total income, $b$ is the base salary, $r$ is the commission rate and $s$ is the sales.

Remember, x% can be written as $\frac{x}{100}$.

First, let's calculate Jill's total income and call it $J$:

J = $40,000 + 15/100*$750,000

J = $40,000 + 15*$7,500

J = $40,000 +$112,500

J = $152,500 Then we can also calculate Shonda's total income and call it $S$: S =$55,000 + 10/100*$750,000 S =$55,000 + 10*$7,500 S =$55,000 + $75,000 S =$130,000

To find out how much more Jill made we need to calculate $J - S$

J - S = $152,500 -$130,000 = \$22,500