anonymous one year ago Which is the solution of the system? A. (-4,2) B. (-3,1) C. (-3,-5) D. (4,-6)

1. anonymous

|dw:1435437755769:dw|

2. anonymous

do i use distributive property???

3. Astrophysics

4. anonymous

yeah nvm i understand it now that i really look at it..its all good

5. Astrophysics

$\frac{ (x+y) }{ (2x-3y) } = -\frac{ 2 }{ 9 }$ is the problem this?

6. Astrophysics

Can you just take a picture of it and upload it

7. anonymous

8. Astrophysics

Oh, that makes sense, they are two different equations right?

9. Astrophysics

Yeah!

10. anonymous

so basically i just use distributive property?

11. Astrophysics

Ok so you have two equations, $x+y=-2$ $2x-3y=-9$ No not quite, so does it ask for any methods, like elimination, substitution, matrices?

12. anonymous

it asks what the solution is

13. Astrophysics

Ok, we can use any method then

14. anonymous

im gonna give you a medal just cuz youve been the most help ive had since ive gotten on here

15. Astrophysics

Lets use substitution, so to do this problem, we want to isolate one of the variables in one of the equations and plug it into the second equation, that will help us find the x value and then we can go back and find the y value. We could also take your options in to our advantage and do it the lazy way but I don't think you will learn that way.

16. Astrophysics

Ok I think drawing it out will make more sense, first you want to label the equations

17. anonymous

Did you read what i said?

18. Astrophysics

|dw:1435438438884:dw| Hey, yes I did thanks :) So lets do this problem now, pick one of the equations and one of the variables to isolate in that equation.

19. anonymous

2

20. Astrophysics

Haha, actually lets pick one as it's a bit more simple to deal with it

21. anonymous

ok 1 it is

22. Astrophysics

Now lets say we solve for x

23. Astrophysics

|dw:1435438607278:dw| so far so good?

24. anonymous

yerp

25. Astrophysics

Ok great, now we want to take this expression and plug it into the second equation, as such |dw:1435438692346:dw| notice how we have removed x from the equation now we can simply solve for the y!

26. Astrophysics

Could you try solving for y? Don't worry about making mistakes long as you're attempting that's awesome.

27. anonymous

|dw:1435438790521:dw|

28. anonymous

is that right???????

29. Astrophysics

Yes, it's being multiplied so you have to distribute

30. anonymous

|dw:1435438885781:dw|

31. anonymous

ill brb i gotta get something..it might be a few minutes...plzzz wait

32. Astrophysics

Not quite, |dw:1435438982368:dw| does that make sense?

33. anonymous

yes sorry for the wait lol

34. Astrophysics

It's ok

35. Astrophysics

Now you want to simplify it, collect like terms and solve for y

36. anonymous

would it be 2-3y or -2-3y?????

37. Astrophysics

I'm not sure what you mean but |dw:1435439329301:dw| so y will be?

38. anonymous

it is -2-3y i got -9=-9

39. anonymous

whhhaaaatt

40. anonymous

ooohhhi did that all wrong i got that now lmao

41. Astrophysics

Ok :), now just solve for y? One step needed

42. anonymous

soo the only answer with y=1 is b...would that be the answer?

43. Astrophysics

Yes, y = 1, but you should make sure to check with x just in case you did not make any mistakes, lets take equation 1 and plug y in it.

44. Astrophysics

|dw:1435439549600:dw| so our solution is (-3,1) yup!

45. anonymous

yayyy its right..thank you so much.. =^w^=

46. Astrophysics

Np :)