Need help don't know what I'm doing

Can someone show me step by step how to do this?

Ellie spent $88.79 at the computer stote. she had $44.50 left to buy a cool hat. how much money did she originally have? write and solve an equation to answer the question.

Asalesperson set a goal to earn $2,500 in august. she receives a base salary of $1,000 per month as well as a 20% commission for all sales in that month. how many dollars of merchandise will she have to sell to meet her goal?