Algebra Question

Question

The Young family and the Martinez family each used their sprinklers last summer. The water output rate for the Young family's sprinkler was 25L per hour. The water output rate for the Martinez family's sprinkler was 30L per hour. The families used their sprinklers for a combined total of 45 hours, resulting in a total water output of 1275L. How long was each sprinkler used?

Answer 1

25x +30y = 1275

x+y=45

25x +30(45-x) = 1275

25x -30x = 1275-45(30)= 1275-1350 =- 75

5x = 75

x =75/5 = 15 hours for Young family

y =45-15 = 30 hours for Martinez family

check the answers

25(15)+30(30) = 375+900 = 1275