Anybody know the slope to this graph?

Alex's monthly take home pay is $2,500. what is the maximum bad debt payment he can maintain without being in credit overload?

Meee i honestly dont know what this question talking about

Astore is having a sale in which all items are reduced by 20 percent. including tax, jennifer paid $21 for a pair of shorts. if the sales tax is 5 percent, what was the original price of the shorts