Question

ngrid and Giovanni each ordered 3 computer games online that cost the same amount. Ingrid used a coupon for $10 off, and Giovanni used a coupon for 8% off. The expression shown below represents the difference between Ingrid’s total cost in dollars and Giovanni’s total cost in dollars.


What is the value of the expression when x = 20?


7.60


10.92


5.20


14.80

Answer 1

Ingrid’s cost = 3x − 10. Giovanni’s cost = 3x(0.92) = 2.76x.
Difference = (3x − 10) − 2.76x = 0.24x − 10.
For x = 20: 0.24(20) − 10 = 4.8 − 10 = −5.2, so the dollar difference is $5.20.

Answer: 5.20