## pinkmommy 2 years ago ...

1. avery23

All you need to do is solve for x in the second equation, and you will get one of the answers.

2. avery23

You should get x=8-y. First add y to the other side, and then divide through by -1.

3. Rosh007

you need to substitute tha value of x into first equation....from second equation.. can you tell me what is your second euation?

4. avery23

You are just trying to find what equation you would substitute in.

5. Rosh007

ok.. here your question says what expression would you substitute into the first equation? that means you just need to find the value to substitue so that you can solve later on BUt you have solved it by following the example in your note

6. avery23

You did that right, but its just wanting you to isolate the second equation for x,i.e. solve for x and that is what your answer should be. The question is not wanting you to work it out. Just find what you are sustituting in.

7. avery23

Yes.

8. Rosh007

so let us go back to the first step... can you just tell me which is first uqtion and second equation.. (it is obivious fromthe options... but I want you to know what you are doing)

9. pinkmommy

i didnt know 8-y was the answer it was a guess first 2x + y = 9 second -x - y = -8

10. Rosh007

yes... now your question says "what expression would you substitute into the first equation? ".... can you tllme what that means?

11. Rosh007

*tell me

12. pinkmommy

-x - y = -8?

13. Rosh007

yes.. ok.. let me help you it means.. you need to find a value to substitute in first equation.. and only we have second equation is left... you are correct

14. Rosh007

now look at the options... which variable is there in options

15. pinkmommy

y

16. Rosh007

yup... so... you have to substitue a value which contain... y.... and also from second equation... so which variable has to be replaced?

17. pinkmommy

x?

18. Rosh007

Yes... and reason?

19. pinkmommy

eliminate to find y? idk

20. Rosh007

yes... exactly right?.... so how you can find that value of x from second equation

21. Rosh007

**Exactly right

22. pinkmommy

so how do i start doing it?

23. Rosh007

ok..so we have second equation.. and ar you convinced that w have to eliminate x and we can do that from second equation?

24. pinkmommy

huh?

25. Rosh007

means we need to find the value of x ( since option is interms of y) to substitute (sorry for my bad english)

26. pinkmommy

thats fine. how do i do that?

27. Rosh007

what expression would you substitute into the first equation? -- from question we have second equation and can you tll me onc again what was second equation?

28. pinkmommy

-x-y=-8

29. Rosh007

welll... what is -x = ???

30. pinkmommy

-1

31. pinkmommy

not trying to rush you but can you hurry && show me how to do this bc my son needs me right now. please && thank you :)

32. Rosh007

can you check again... Clue ( the equality will not change when same number is added or subtracted or divided or multiplied)

33. Rosh007

mmmm...ok... add -y to both sides of equal sign what you get?

34. pinkmommy

y = -8 - x

35. Rosh007

-y and + y cancels so what is left?

36. pinkmommy

i gotta go sorry. thanks for all of your help.

37. Rosh007

Ok I will write the steps.. so if you have any doubt can post here

38. Rosh007

sorry this is corrct -x-y+y =-8+y (not -8-y, i made a mistak there) now -x = -8+y multiply both side by - sign we get x = 8-y which is th answer i am so sorry that I had to right the steps directly.. but hope you will commet.. if this dosn't get you..