John worked a total of 12 hours babysitting and tutoring

Question

He made $8.00 an hour babysitting

He made $15 an hour tutoring

John made a total of $131.00

How many hours did he spend tutoring?

Answer 1

T + B = 12

15T + 8B = 131

At least for me it is usually easier to solve by elimination, like this:

8T + 8B = 96

Subtract

7T = 35

T = 5

B = 7