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## anonymous one year ago What values of x and y satisfy x − 3y = 4 and 2x + y = 7 simultaneously?

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1. Loser66

who will work? you or me?

2. anonymous

its Solving Linear Systems Using Linear Combinations

3. anonymous

idk how to work them out

4. Loser66

willing to work?

5. anonymous

willing to work?...i dont understand

6. Loser66

You don't know how to do, but if I guide and YOU are willing to work, we can work together to get the answer. If you don't want to work on it, OOOOOOOOOOOOOK, both us go to bed. hahahaha....

7. anonymous

well yea im willing to work on it

8. Loser66

ok, what is the fist equation?

9. anonymous

x − 3y = 4?

10. Loser66

yup, multiply both sides by 2, what do you get?

11. anonymous

2x-3y=8

12. Loser66

why -3y?

13. anonymous

idk its jus there

14. Loser66

hey, |dw:1433204298762:dw|

15. anonymous

ooooooo ok so u distribute

16. Loser66

yup, now what is the second equation?

17. anonymous

2x + y = 7

18. Loser66

ok, let them close to each other, and then subtract them, what do you have?|dw:1433204441490:dw|

19. anonymous

-5y=7?

20. Loser66

redo

21. anonymous

idk how u would get it

22. Loser66

You should be aware that I am ssssssssssso patient. I won't indulge you. You must work on it by yourself

23. Loser66

|dw:1433204716278:dw|

24. Loser66

=?

25. anonymous

-7y-1

26. anonymous

=1

27. Loser66

-7y =1 okkkkkk

28. Loser66

divide both sides by -7 , what do you get?

29. anonymous

y=-7 maybe?

30. anonymous

or positive 7

31. Loser66

|dw:1433204871798:dw|

32. anonymous

so when u divide 1 by a larger # it becomes a fraction?

33. Loser66

now, replace y = -1/7 into the second equation, what do you get?

34. Loser66

yup

35. Loser66

|dw:1433205038742:dw|

36. anonymous

|dw:1433205117411:dw|

37. Loser66

+1/7 both sides.

38. anonymous

-2x=-1?

39. Loser66

|dw:1433205229223:dw|

40. Loser66

|dw:1433205288926:dw|

41. anonymous

tbh im kinda confused on this step

42. Loser66

your ORIGINAL second equation is 2x +y = 7 replace y = -1/7 in, you have 2x-1/7 =7. Why confuse?

43. anonymous

ok i get tht part

44. Loser66

now, you have 2x = 50/7 divide both sides by 2, you get x. combine with y =-1/7 above, you have the solution. done

45. anonymous

ok i get it thx i appreciate it

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