## anonymous one year ago -3x-6y=21 3x-6y=-9 System Of Elimination - Only Need Steps . Thanks

1. anonymous

-5,-1

2. anonymous

the x's with the x's and the y's with the y's

3. anonymous

4. anonymous

And I Did That

5. anonymous

6. LynFran

note: by adding the 2 equations we eliminate the x term...

7. anonymous

Ok

8. LynFran

so |dw:1439780091924:dw| please simplify what do we have?

9. LynFran

whats -6y-6y=? whats 21-9=?

10. anonymous

-12y=12

11. LynFran

good now we need the y variable by itself... but right now -12 is being multiplied to y (-12y)... how can we get y alone? do u know?

12. anonymous

Divide

13. LynFran

good so|dw:1439780478252:dw|

14. anonymous

0

15. LynFran

no if we divide 1/1 we get 1 so any # divided by itself is 1 ..but noted the negative....

16. anonymous

Whats Being Divided By One Up There

17. LynFran

|dw:1439780655225:dw|

18. anonymous

ok

19. anonymous

12/-12 =0

20. LynFran

1 divided by 1= 1 2 divided by 2= 1 3 divided by 3 =1 ....

21. tkhunny

\(\dfrac{12}{12} = 1\) \(\dfrac{Dog}{Dog} = 1\) \(\dfrac{Pittsburgh}{Pittsburgh} = 1\)

22. anonymous

^ oooohhh i get it now

23. LynFran

so whats y=? note the negative sign..

24. anonymous

-1

25. LynFran

good now since we have y=-1 we can now find the value of x by? u have any idea? ...

26. LynFran

how to find that...

27. anonymous

28. LynFran

no we can substitute the value of y=-1 into the given equations... equation 1 or equation 2 it doesnt matter..u will be given the same result of x..

29. anonymous

ok

30. LynFran

so using equation 1 |dw:1439781130011:dw|

31. LynFran

whats (-6)*(-1)=?

32. LynFran

whats negative 6 times negative 1 =?

33. anonymous

-6

34. LynFran

a negative # time a negative #= a positive #

35. anonymous

oh yea

36. LynFran

so ....

37. anonymous

6

38. LynFran

|dw:1439781539647:dw| now we need to get x on one side of the equation alone...to do that we can subtract 6 to both sides of the equation...

39. LynFran

|dw:1439781655064:dw|

40. anonymous

DIVIDE 3X FROM BOTH SIDES OF THE EQUATION

41. LynFran

no we subtract 6 from both sides of the equation leaving |dw:1439781779950:dw| whats 21-6=?

42. anonymous

15

43. LynFran

ok good can you by using draw' show me the next step |dw:1439781903092:dw|

44. LynFran

|dw:1439781938626:dw|

45. anonymous

|dw:1439774773769:dw|

46. LynFran

no... we can divide by x ... we need x to be alone on one side of the equation ..

47. LynFran

|dw:1439782133454:dw|

48. LynFran

|dw:1439782193901:dw|

49. LynFran

note the negative sign...

50. anonymous

-5

51. LynFran

correct

52. LynFran

now we can do a check to make sure thats our solution by simply substituting the values we just find into the given equation so... |dw:1439782336135:dw|

53. anonymous

Yay ! Lol

54. LynFran

ok

55. LynFran

any question?

56. anonymous

No Thanks

57. LynFran

ok welcome