Part A: The discounted monthly fee is $22.49 (original cost of $29.99 multiplied by 75%, the amount the customer would pay since 25% is discounted.) Since you would also pay $44.99 for setup, your equation is $44.99+$22.49m
Part B: Add 1.08 (108%; the customer pays 100% of the cost plus 8% more for tax) to your equation for the sales tax. 1.08(44.99+22.49m)
Part C: Plug in 4 for m (m represents months).
1.08(44.99+22.49•4)
1.08(44.99+89.96)
1.08(134.95)
$145.75
Hope that helps. Let me know if you need more assistance :)
