Part A: 20 shows $20 which Cory earns by mowing one lawn. 9 shows $9 which he earns by trimming one hedge. x shows the number of lawns. y shows the number of hedges. Part B: There are two terms in this expression. 20x which shows the total earning of Cory by mowing lawns. 9y which shows his earning by trimming hedges. It can be judged by the description of rates explained in part A. Part C: From explanation given in Part C, we can easily see that the expression 9y is used for the total earned from trimming hedges.
