3y+8x+9
3y+8x=16

nanniedonna, your question makes no sense. First of all, the top one isn't even an equation (there's no equals sign). In the subject, you have an equals sign before the 9, but no operators?

Anyway, even if you meant to put an "=" instead of a "+", it STILL doesn't make sense. The left side would be the same for both equations, but equal to a different constant on the right. The left side can't be equal to 9 and 16 at the same time.

So if you want help, try proof-reading your question before you post it.

If your two equations are:

3y+8x=9
3y+8x=16

Then, you cannot solve this. Graphing those two equations will show you that these two lines are parallel to each other and therefore, don't ever meet. Since solving two equations means to find the point of intersection of two graphs, there is no solution to this problem.