## anonymous one year ago The Scott family and the Phillips family each used their sprinklers last summer. The water output rate for the Scott family's sprinkler was 30L per hour. The water output rate for the Phillips family's sprinkler was 20L per hour. The families used their sprinklers for a combined total of 50 hours, resulting in a total water output of1300L. How long was each sprinkler used? Scott family: hours Phillips family: hours Will medal

1. anonymous

@Vocaloid

2. Vocaloid

write and solve a system of equations

3. anonymous

I dont know how to do that

4. Vocaloid

start by defining two variables let s = number of hours used for the Scott family let p = number of hours used by the Phillips family

5. anonymous

yea

6. Vocaloid

p + s = 50

7. anonymous

ok

8. Vocaloid

20p + 30s = 1300 p + s = 50 solve for p and s

9. anonymous

thats the part im stuck on

10. Vocaloid

start by multiplying the second equation by 20

11. anonymous

which one

12. Vocaloid

I said the second one

13. anonymous

doesnt make any sense

14. Vocaloid

here are your two equations 20p + 30s = 1300 p + s = 50 multiply the second equation by 20

15. anonymous

20p+20s=100

16. Vocaloid

almost

17. Vocaloid

50*20 = ?

18. anonymous

1000

19. Vocaloid

good.

20. Vocaloid

now we have 20p + 30s = 1300 20p + 20s = 1000 now subtract the two equations.

21. anonymous

10s=300

22. Vocaloid

good now find s...

23. anonymous

s=30

24. Vocaloid

great, now go back and find p

25. Vocaloid

we know that p + s = 50, so what is p?

26. anonymous

25

27. Vocaloid

nope.

28. Vocaloid

s = 30 p = ?

29. anonymous

20

30. Vocaloid

great.

31. anonymous

ty have a few more up to helping me