You earned $141 last week babysitting and cleaning. You earned $5 per hour babysitting and $7 per ho

You earned $141 last week babysitting and cleaning. You earned $5 per hour babysitting and $7 per hour cleaning. You worked 9 more hours babysitting than cleaning. How many hours did you work last week?

Let b be the hours of babysitting and c be the hours of cleaning. We're given two equations:

1. b = c + 9
2. 5b + 7c = 141

Substitute equation (1) into (2):
5(c + 9) + 7c = 141

Multiply through:
5c + 45 + 7c = 141

Combine like terms:
12c + 45 = 141

Typing this equation into our search engine, we get:
c = 8

Now substitute this value of c back into Equation (1):
b = 8 + 9
b = 17

The total hours worked (t) is:
t = b + c
t = 17 + 8
t = 25