All separable equations are exact?

[epiclesis]

How can I show that the separable equation dy/dx = M(x)N(y) is also exact?

Any ideas?

Thanks in advance!

-epiclesis

[h2]

dy/dx = M(x)N(y) implies
M(x)dx - dy/N(y) = 0
is this equation exact?

[HallsofIvy]

Of course, that should be "M(x)dx- N(y)dy= 0".