On a map, 3/8inch represents 15 miles. what is the distance represented 1 1/8 inches on the map?

First divide 1 1/8 by 3/8 to see how many 3/8 distances you have, then multiply that by 15 to get total miles:

convert 1 1/8 into an improper fraction: 1 1/8 =  1 = 8/8 + 1/8 = 9/8

now divide 9/8 by 3/8 : 9 /3 = 3 8/8 = 1 = 3/1 = 3

you have 3 3/8 distances

each one is 15 miles so 15 x 3 = 45 miles

The answer would be (8+7z)/5