## anonymous one year ago help me please

1. anonymous

Solve the system by the addition method. x2 - 3y2 = 1 3x2 + 3y2 = 15 A. {( 1, 2), ( -1, 2), ( 1, -2), ( -1, -2)} B. {( 1, 2), ( -1, -2)} C. {( 2, 1), ( -2, 1), ( 2, -1), ( -2, -1)} D. {( 2, 1), ( -2, -1)}

2. anonymous

@isaac4321

3. anonymous

._.

4. JoannaBlackwelder

Any thoughts on how to start?

5. anonymous

substitute the x and the y maybe

6. JoannaBlackwelder

Can you show me what you mean?

7. anonymous

1+2 - 3+2 -1= 1

8. JoannaBlackwelder

Hm, how did you get that?

9. anonymous

x2 - 3y2 = 1 substituted in this equation

10. JoannaBlackwelder

Hm, I'm not sure what you mean, but the question states to solve by the addition method. Not substitution.

11. JoannaBlackwelder

The addition method works by adding the equations together in a way that cancels out one of the variables.

12. anonymous

ok so how do i do that

13. JoannaBlackwelder

|dw:1439917233250:dw|

14. JoannaBlackwelder

See how I canceled out the y's?

15. anonymous

yes

16. JoannaBlackwelder

Sweet. Can you solve the equation for x?

17. anonymous

x=2

18. anonymous

or x=-2

19. JoannaBlackwelder

Exactly! Both are possible solutions for x! :-) Any ideas what to do from here?

20. anonymous

solve for y next maybe

21. JoannaBlackwelder

Yep, great! Any thoughts on how to do that?

22. anonymous

y=1 or y=-1

23. JoannaBlackwelder

Good, but which x goes with which y?

24. anonymous

i got that buy soing what you did in your drawing but i cancled out x then i solved what i got from that to get my answer

25. JoannaBlackwelder

Ok, that's cool. But if you plug them back in, which ones make true statements out of the equations?

26. anonymous

(y=1 x=2) (y=-1 x=-2)

27. JoannaBlackwelder

Are those the only options?

28. anonymous

idk are they

29. JoannaBlackwelder

Try other options and see if they work too.

30. anonymous

i cant get any of them to work

31. anonymous

so is my anser d right

32. JoannaBlackwelder

33. JoannaBlackwelder

|dw:1439918310526:dw|

34. anonymous

35. JoannaBlackwelder

No, that one has the x and y values flipped.

36. anonymous

ok imma stop guessing its c

37. JoannaBlackwelder

Sounds good

38. anonymous

thnx

39. JoannaBlackwelder

yw

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