3x =2y = 17

2x-y =9

and

3x+y = 3
x+2y = -4

How do I do these??

22Z 6Y

These are simultaneous equations. You have a typo in #1.
For the second set, just multiply equation 1 by 2, then subtract equation 2 from equation 1 (which will eliminate y), then solve for x. Post your work if you get stuck and need further assistance.

These are simultaneous equations. You have a typo in #1.
For the second set, just multiply equation 1 by 2, then subtract equation 2 from equation 1 (which will eliminate y), then solve for x. Post your work if you get stuck and need further assistance.