1. the total cost after tax to repair deborah’s computer is represented by 0.08(50h)+50h, where h represents the number of hours it takes to repair deborah’s computer. what part of the expression represents the amount of tax deborah has to pay? explain.

0.08(50h)+50h is the total cost including the tax on it.

now, the tell-tale part is the 0.08, the decimal bit, because is multiplying 50h.

if, say to fix Deborah's computer took 5 hours, then h = 5, the cost the fellow is charging her for his work is 50h, if h = 5, then 50(5) or 250 bucks.

That simply means, the charge per hour to fix her machine is 50 bucks, for 5 hours, that's 250, or 50(5).

the 0.08(50h) is simply multiplying that 50h, so 0.08 is just  

so, the 0.08 in decimal format is simply applying an 8% tax on 50h, whatever "h" happens to be.

1.17+3.99a. you combine the terms with a to create 3.99 and the 1.17 stays because it has no like terms or a variable