Ryan works mowing lawns and babysitting. He earns $8.20 an hour for mowing and $7.70 an hour for babysitting. How much will he earn for 3 hours of mowing and 7hours of babysitting?

Step-by-step explanation:

Ryan works mowing lawns and babysitting. He earns $8.20 an hour for mowing and $7.70 an hour for babysitting. Therefore, the expression for the total amount that he would earn if he mows lawns for x hours and babysits for y hours would be

8.2x + 7.7y

Therefore, the amount that he would earn for 3 hours of mowing and 7hours of babysitting is

(8.2 * 3) + (7.7 * 7)

= 24.8 + 53.9

= $78.7