A computer repair shop charges a flat rate of $50 plus $35 per hour spent repairing each computer. How much will the repair shop charge if the shop does 2.5 hours of work?

So we know no matter what, there will be a flat charge of $50, and then $35 for ever hour

Since it is 2.5 hours of work, it will cost 35 * 2.5, but we need to include the flat rate so we get the expression

50 + (35*2.5) = 50 + 87.5 = $137.50

50 + (35*2.5) = 50 + 87.5 = $137.50