Question

the plumber charges $50 for the first visit plus $8 per hour of work . if the plumbers total bill is $290 how many hours did he work

Answer 1

h is the variable I used for hours worked
290=(8*h)+50 (known 50 dollar fee plus 8$ / hr)
subtract 50 from both sides
240 = 8h
divide both sides by 8
h=30

He worked 30 hours.