I have two problems that I need help with
I.
3x-2y=8
-12x+8y=32


II.
-4x+3y=5
12x=9y=15

II.
-4x+3y=5
12x=9y=15

You know how elimination works! If so, then, try to make the two equations as similar as possible, for a certain variable. (i suppose you meant 12x+9y=15)
For example, multiplying the first one by 3 will have -9y for the y-variable, which is pretty close to the second one.

-4x+3y=5
-12x+9y=15

12x+9y=15

Add both equations:

0x + 18 y = 30

therefore

18y = 30

As for the first one, i can see that they're parallel lines (if you draw their graphs, you'll see the same thing) and so, do not intercept and so, there are no solutions). That'll be the same thing if you actually meant that the second equations were:

-4x+3y=5
12x-9y=15