## dumbsearch2 2 years ago Solve the following system using the substitution method: 2x = y 6x + 4y = -14

1. AravindG

ok giveb y=2x

2. AravindG

*given

3. AravindG

now replace y in second equation with 2x

4. AravindG

then solve for x

5. AravindG

having got x substitute its value in first equation to get y

6. ParthKohli

So you understand Aravind's explanation?

7. ParthKohli

LOL, I am red as long as I don't refresh

8. dumbsearch2

haha! ;D

9. dumbsearch2

no i don't understand. :(

10. AravindG

where exactly you have doubt @dumbsearch2 ?

11. hba

Plug in y=2x in eq(2)

12. dumbsearch2

how to find x

13. ParthKohli

$\color{#C00}{2x} = y$$6x + 4\color{#T00}{\cdot y} = 6x + 4\cdot \color{#C00}{2x}$

14. dumbsearch2

how to find x? cause to find y you need to know x right?

15. hba

how to find y ? cause to find x you need to know y right?

16. AravindG

you have an equation containing only x when you substitute y with x.Then solve for x

17. AravindG

gt it now @dumbsearch2 ?

18. dumbsearch2

nope. :( sorry I'm dumb...

19. AravindG

try to read the replies above again, try to understand what is said .

20. Callisto

The first equation we have is 2x = y, that is the same as y=2x. The second equation we have is 6x + 4y = -14. Now, we put y=2x into the second equation. That is whenever we see "y" in the second equation, we re-write it as "2x" So, we get: 6x + 4 (2x) = -14 Can you solve this?

21. ParthKohli

You know that $$2x = y$$, right? So can you say that $$6x + 4y =14$$ can be written as $$6x + 4(2x) = 14$$?

22. dumbsearch2

x = -4 right?/

23. dumbsearch2

no i mean -1? no?

24. ParthKohli

Hmm... yes!

25. dumbsearch2

so y = -2! so y = -2, and x= -1! no?

26. ParthKohli

Sorry, it's not $$6x + 4y = 14$$. I got my reply wrong :-P

27. ParthKohli

Yesh!

28. Callisto

*Clapping hands*

29. ParthKohli

Yay!

30. dumbsearch2

:DD thanks so MUCHJ GUYS! im trying so hard to finish math online course for tomrrow... it closes on tomorrow, and I've got 2 units to do online!!! (each unit has like 4 lessons and 4 quizes) I'm kinda bad at the subtituation method and stuff, wish I would understand! it techinically is tomorrow, I mean it's the very very very early morning right now!!i know! I'm trying to use openstudy to help me too... (that's how I stumbled upon this site today!)

31. dumbsearch2

So like this! (Confirm! :))

32. ParthKohli

Yes :-)

33. dumbsearch2

yeaa! ;D

34. dumbsearch2

got a 75% grade in the quiz, not bad. :D