[merrafi]

y=.5x+9
2y-x=1 please tell what it equals

[jcaron2]

Unless you typed the equations incorrectly, there is no solution.

If you're familiar with plotting equations like these and/or solving systems of equations graphically, you may recognize that these are the equations of two parallel lines. Parallel lines never intersect; therefore, there is no point through which both lines pass. In other words, no (x,y) pair exists which simultaneously satisfies both equations.