## gerryliyana Group Title I need help ! Pleaseee Solve (x-2y +1) dx + (4x -3y -6) dy = 0 one year ago one year ago

1. xon1300 Group Title

use green's theorem ( http://en.wikipedia.org/wiki/Green%27s_theorem )

2. gerryliyana Group Title

Seriously??? can you tell me how to solve it?

3. xon1300 Group Title

It's been a while since i took calculus 3

4. gerryliyana Group Title

then???

5. gerryliyana Group Title

have you any idea, @Cynosure-EPR ?????

6. Cynosure-EPR Group Title

I'm sorry =( I do know how to do it but I'm rushed with a programming assignment (worth 40% of grade) due at midnight =(

7. gerryliyana Group Title

ok no problem @Cynosure-EPR :) good luck for u :)

8. gerryliyana Group Title

@zepp have u any idea??

9. zepp Group Title

Nope, I'm only at Calc II, sorry ):

10. gerryliyana Group Title

ok np @zepp thank u for coming :)

11. mahmit2012 Group Title

|dw:1354582292989:dw|

12. ChmE Group Title

$(x-2y +1) dx + (4x -3y -6) dy = 0$$-(x-2y +1) dx = (4x -3y -6) dy$$\frac{ dy }{ dx }=\frac{ -(x-2y+1) }{ (4x -3y -6) }$

13. ChmE Group Title

Do you know how to do separation of variables? http://en.wikipedia.org/wiki/Separation_of_variables

14. ChmE Group Title

This looks like a diff eq question

15. ChmE Group Title

nvm, I don't think we can use that here

16. gerryliyana Group Title

then ???? how to solve y?? i really know separation variable, but in this case that method cannot work,

17. gerryliyana Group Title

yes.., i think so.., we cannot use that in this case.., :)

18. ChmE Group Title
19. ChmE Group Title

My teacher skipped partial derivatives and that looks like what is needed for this problem. I'm going to tapout. Good luck

20. gerryliyana Group Title

i see.., wonderful site for me.., thank u @ChmE,

21. sirm3d Group Title

solve the system of equation $\large \left(\begin{matrix}x-2y+1=0 \\ 4x-3y-6=0\end{matrix}\right)$

22. sirm3d Group Title

when you get the solution, say x0 and y0, use u = x - x0 and v = y - y0. try this @gerryliyana

23. gerryliyana Group Title

ok.., i'll try

24. sirm3d Group Title

did you get this DE? $\large (u-2v)du + (4u-3v)dv=0$ x changed to u, y changed to v, the constants +1 and -6 disappeared.

25. gerryliyana Group Title

$\left( \frac{ x - 2y + 1 }{ 4x -3y - 6 } \right) \times \left[ \frac{ 4 }{ 1 } \right]$ $\left( \frac{ 4x - 8y + 4 }{ 4x - 3y -6 } \right) = 0$ $\left( \frac{ 4x - 8y = -4 }{ 4x -3y= 6 } \right)$ -------------------------------------------- __ $-8y -(-3y) = -10 \rightarrow y = 2$ $4x - 3(2) = 6 \rightarrow x = 3$

26. sirm3d Group Title

on the right track. now, u = x - 3 and v = y - 2

27. gerryliyana Group Title

OMG..., my connection is lost, and I lost all my type, :(

28. sirm3d Group Title

hahaha. enter them a few equations at a time.

29. sirm3d Group Title

don't worry. you are not the first one.