Mitch borrowed $500 from his brother. he mows lawns after school and on the weekends. he charges $32 a lawn and pays his friend tom $12 a lawn to . mitch plans to repay his brother 40% of what he earns on each lawn. which expression represents this situation?

Since he borrowed 500, we start with -500. next, if the amount of lawns moved is l, then since he charges 32 dollars for each lawn he gets 32*l to add to it. after that, since he pays his friend 12 dollars per lawn, we subtract 12*l from the expression. in addition, since he pays his brother 40% (or 0.40 by moving the decimal 2 places) for each lawn, with the cost of each lawn being 32, we get that he pays his brother 32*0.40*l. add all these up to get 
-500+32l-12l-(32*0.4*l)=-500+20l-12.8l=500+7.2l

The answer to that is 6