Answer: 133
Step-by-step explanation: First thing you need to do is find the unit rate which means how many windows can he clean in one hour. We know he cleaned 38 windows in 2 hours so divide 38 by 2 to get unit rate
38 divided by 2 is 19 so that is the amount of windows cleaned in 1 hour
so to find the amount in 7 hours multiply the unit rate by 7
19 times 7 is 133 so he can clean 133 windows in 7 hours