What is my answer its confusing

Question

Climbing at an indoor rock-climbing gym cost $8 per hour. Lizbeth has $30 gift card to spend at the gym. Write and algebraic expression for the dollar amount Lizbeth will have left on the card after she spends h hours climbing. Can Lizbeth climb for 4.5 hours using only her card? Explain how you know.

Answer 1

d represents amount on the card

h represents the hours she climbs

d = 30 - 8h

 

For 4.5 hours

 

d = 30 - 8(4.5)

d = 30 - 36

 

No, she does not have enough money.