prealgebra
posted by Dj .
Mrs. Boyd went shopping at city center Mall. she parked her car in the parking garage. The cost for parking was $1.00 for the first hour and $0.75 for each additional 1/2 hour. Mrs. Boyd paid $4.75 for parking. Write an equation to find how long Mrs. Boyd was shopping. How long did she shop? Explain how you arrived at your equation and show your work to solve your equation.
Can someone please help me with this problem?

She shopped for 3 1/2 hours.
If you write the equation and explain it, we'll be glad to check it. 
Since he paid more than $1, he must have parked more than one hour. Let T be the number of hours parked. T1 is the number of hours parked at the lower rate.
Your equation is:
4.75 = 1.0 + 0.75*2*(T1)
which can be rewritten as
4.75 = 1 + 1.5 (T1)
The "2" gets multiplied in because they charge by the half hour after one hour.
Solve that equation for T.