Acar wash charges a flat rate for the first 8 minutes of washing time and also charges a certain amount for each additional minute of washing time. gina took 12 minutes to wash her car and it cost her a total of $5.00. kris took 17 minutes to wash his truck at a total cost of $6.25.
how much is the is the flat rate for the first 8 minutes? show equation to find answer. plz answer this word problem.

Flat rate = x

so for the first eight minutes they both have the same rate
so this is also true
Gina took 4 minutes to wash her car and it cost her a total of $5-x
Kris took 9 minutes to wash his truck and it cost him a total of $6.25-x
so for overtime 4mins=5-x,  9mins=6.25-x
4 times 9 = 36 so
36 mins = (45-9x)=(25-4x)
so 45-9x=25-4x
subtract 25 from both sides and get
20-9x= -4x
subtract add 4x to both sides
20-5x=0
factor out the five
5(4-x)=0
(4-x) must =0
4-x=0
add x to both sides
4=x
it cost $4 for flat rate

31/6= 19/6 19/6 *1/7=19/42