## anonymous one year ago The Jones family attends a movie for $47.00 with two adults and three kids. The Smith family attends when some friends are in town for$74.75 with three adults and five kids. How much does the Ramirez family have to pay with adults and four kids

1. anonymous

set up some equations

2. anonymous

what kind??

3. anonymous

Jones family: 2*adults + 3*kids = \$47 total 2*a + 3*k = 47 2a + 3k = 47

4. anonymous

all three of those equations represent the same thing

5. anonymous

can you set up an equation for the Smith family now?

6. anonymous

3a+5k=74.75 whats next?? @bi

7. anonymous

perfect now you have two equations and two unknowns, can you solve this system for a and k? 2a + 3k = 47 3a + 5k = 74.75

8. anonymous

how do you do that? sorry

9. anonymous

are you allowed to use a calculator on tests?

10. anonymous

no

11. anonymous

hmm ok, the easiest way would be either elimination or substitution, which do you prefer?

12. anonymous

substitution

13. anonymous

what is the last sentence supposed to say? "How much does the Ramirez family have to pay with adults and four kids"

14. anonymous

its missing the number of adults

15. anonymous

with four adults and four kids

16. anonymous

a. y=45+3k?

17. anonymous

ok solve one of those 2 equations for either a or k, you choose

18. anonymous

hmm close but not quite

19. anonymous

2a + 3k = 47, lets solve for a, so first subtract 3k from both sides

20. anonymous

2a = 47 - 3k, now divide both sides by 2

21. anonymous

22

22. anonymous

no, a = (47 - 3k) / 2

23. anonymous

do you understand?

24. anonymous

and what will be the answer

25. anonymous

to the whole problem?

26. anonymous

just to the first one

27. anonymous

we are working on it

28. anonymous

do you understand how we got a = (47 - 3k) / 2

29. anonymous

yes

30. anonymous

ok so now you know the value of a, we cannot plug it back into the same equation because we will not get any new information, so lets plug it into the other equation

31. anonymous

can you please plug what we found for a, into the other equation?

32. anonymous

3a=74.75-5k

33. anonymous

thats true but you need to plug what we found for a into that equation

34. anonymous

so that we can solve for k

35. anonymous

can u plug it in.. I'm kinda lost

36. anonymous

ok lets start again, because me doing it for you wont help anyone

37. anonymous

we have these two equations that we came up with 2a + 3k = 47 3a + 5k = 74.75

38. anonymous

we looked at the first equation and solved for a 2a + 3k = 47 2a = 47 - 3k a = (47 - 3k) / 2

39. anonymous

now we plug that value for a, into the second equation 3a + 5k = 74.75 3(plug in here) + 5k = 74.75

40. anonymous

go for it

41. anonymous

3(47-3k)+5k=74.75

42. anonymous

thats very close but you left out the divide by 2, i will put it in for you 3((47-3k)/2)+5k=74.75

43. anonymous

$$3*\frac{47-3k}{2} + 5k = 74.75$$

44. anonymous

now you need to solve that for k

45. anonymous

by the way elimination method would have been much easier, but thats ok this is good practice

46. anonymous

so solve that for k and what do you get for k?

47. anonymous

im not sure how you do it

48. anonymous

maybe it will help to write (47 - 3k) / 2 as separate fractions, can you do that?

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