Originally Posted by

**Rapha** Hi there

On his first job:

he used EACH PIECE ...

what does that mean? He used the sprayer for 6 hours and he used the generator for 6 hours,

=> 6*CostSprayer + 6*CostGenerator = $90

Because cost = 90$

On his second job:

He used the sprayer for 4 hours

=> 4*CostSprayers

and used the generator for 8 hours

=> 8*CostGenerator

at total cost =$100

=> 4*CostSprayer + 8 CostGenerator = $100

(of course you add CostSprayer and CostGenerator to get the total costs)

Thus there are to equations

6*CostSprayer + 6*CostGenerator = $90

4*CostSprayer + 8 CostGenerator = $100

Can you solve it?

Solution:

CostSprayer = $5 per hour, CostGenerator $10 per hour