Algebra Help

Question

The Tran family and the Moore family each used their sprinklers last summer. The water output rate for the Tran family's sprinkler was 25 L per hour. The water output rate for the Moore family's sprinkler was 35 L per hour. The families used their sprinklers for a combined total of 55 hours, resulting in a total water output of 1675 L. How long was each sprinkler used?

Answer 1

Let x = the number of hours the Tran family sprinkler was used

Let y = the number of hours the Moore family sprinkler was used

x + y = 55     y = 55 - x

25x + 35y = 1675

25x + 35(55 - x) = 1675

25x + 1925 - 35x = 1675

-10x = -250

x = 25 hours

y = 55 - 25 = 30 hours