Answer:
The expressions for each statement are as follows:
a: 2500+(0.10*2500)
b: 40 * 0.85
c: 250 + (0.075*250)
Explanation:
Part a:
Given
Salary = $2500
Percentage of raise = 10%
The new salary will be:

Part b:
Given
Total questions = 40
Percentage of correct answers = 85%
The required expression for correct answers is:

Part c:
Given
Price of phone = $250
Percentage of sales tax = 7.5%
The required expression is:

Hence,
The expressions for each statement are as follows:
a: 2500+(0.10*2500)
b: 40 * 0.85
c: 250 + (0.075*250)