DragonFlame one year ago Solve, using the substitution method. 4x + 2y = 11 x – 2 = – 2y

1. DragonFlame

Is \[2y=11-4x\] Right?

2. Potatoes.ramu

Multiply the second equation by 2

3. Potatoes.ramu

and then subtract it from the first

4. DragonFlame

Ok, so \[2x-4=-4y?\]

5. Potatoes.ramu

Wait.. actually multiply the second equation by 4. That way you eliminate the x term

6. DragonFlame

\[4x-8=-8y\]

7. DragonFlame

How would I subtract it from the first equation? X becomes eliminated than what?

8. DragonFlame

@hartnn

9. Potatoes.ramu

When x is eliminated, you can find the y term

10. hartnn

substitution method. (not elimination method) 4x + 2y = 11 x – 2 = – 2y (find 'x' from here, by adding 2 on both sides)

11. Potatoes.ramu

Once you find the y term, you can substitute it in any of the above equations, and then you get x.

12. DragonFlame

x=y?

13. DragonFlame

So 6y=11?

14. Potatoes.ramu

@hartnn you'll still have the y term

15. hartnn

x – 2 = – 2y x = 2-2y plug this in 1st equation 4(2-2y) +2y =11 simplify and get y

16. hartnn

ask if you don't get that ^

17. Potatoes.ramu

@hartnn , but can't you solve it using elimination as well?

18. DragonFlame

8-8y+2y=11

19. DragonFlame

-10y=3?

20. hartnn

the system can be solved by elimination method, but since the question specifically asks for substitution, we need to use substitution

21. hartnn

-8y +2y = ... ?

22. DragonFlame

6y

23. DragonFlame

8-6y=11 -6y=3 y=-1/2

24. hartnn

YES :)

25. hartnn

now find x

26. DragonFlame

Okkkkk :)

27. DragonFlame

x=3

28. DragonFlame

So its this bit.ly/1ewUix3

29. hartnn

\(\huge \checkmark \)

30. DragonFlame

(3,-1/2) Right?

31. hartnn

yes, it is correct.

32. DragonFlame

Thanks! Should I give the medal to potatoes or you? He tried... but you helped

33. hartnn

i'm not here for medals. you understand thats my medal :)

34. DragonFlame

:D

35. Potatoes.ramu

Also.. I'm a she :) And my method was wrong for this problem! Sorry!