Problem
Austin takes classes at both Westside Community College and Pinewood Community College. At Westside, class fees are $\$ 98$ per credit hour, and at Pinewood, class fees are $\$ 115$ per credit hour. Austin is taking a combined total of 20 credit hours at the two schools. Suppose that he is taking w credit hours at Westside. Write an expression for the combined total dollar amount he paid for his class fees. \[ \text { total paid (in dollars) }=\mathbb{0} \]
Solution
Step 1 ：Calculate the cost of Austin's classes at Westside: $98w
Step 2 ：Calculate the cost of Austin's classes at Pinewood: $115(20 - w)
Step 3 ：Find the combined total dollar amount Austin paid for his class fees: $98w + $115(20 - w)
Step 4 ：Simplify the expression: $98w + $115(20 - w)
Step 5 ：Combine like terms: $98w + $2300 - $115w
Step 6 ：Simplify further: $2300 - $17w
Step 7 ：Final Answer: \(\boxed{2300 - 17w}\)
