Solve the following system by graphing. If there isn't a unique solution to the system
5x-3y=-36
3x+5y=26
you can get excellent graphing help here:
http://rechneronline.de/function-graphs/
but you need to enter functions of x. So, solving for y, you have
y = (5x+36)/3
y = (26-3x)/5
Enter those two functions and set the range on the y-axis to -10:10 and you will see the solution.