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?

Let's take this one at a time starting from the brother's net income because this would be the root basis. We let x be the number of lawns his brother and Tom mowed. 

Brother's Net Income = 32x - 12x = 20x

Mitch promises to pay the borrowed money of $500 plus 40% of what his brother earns. The algebraic equation for this is:

Mitch's payment = $500 + 0.4(20x) = $500 +$8x

the law of definite proportions states samples of a compound will always contain the same proportion of elements by mass. in other words, a given compound will always contain the same elements in the same proportions by mass.the law of multiple proportions states when two elements combine with each other to form more than one compound, then the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers.