P(t)=number of sheet of paper after t minutes. p(t) will have to be equal to 0, wnen the printer use all 100 sheets of paper; Therefore; if p(t)=0 Then:
-8t+100=0
We solve this equation. -8t+100=0 8t=100 t=100/8 t=12.5
Answer: the printer prints 100 sheets of paper in 12.5 minutes.