Solve the system by substitution:
2x-y=5
-2x+y=7

Question

anonymous · Answer

Solve one of the equations for y, then place that answer into the other equation and solve for x, then take that answer and put it back into the first equation. 
y=2x+7
2x-(2x+7)=5
......this looks wrong, give me a second..

anonymous · Answer

I'm either not doing the math correct or those equations are wrong, it keeps telling me that there is no x.....

anonymous · Answer

Oh. Well those are the right equations.

cruffo · Answer

when you get an answer like -7 = 5 which is not true, that just means there is no solution.  The lines are parallel (same slope, different y-intercept).