You don't need always matrix help to know about the solution of linear equations...when equation are complex like with 3 or more unknown variables , go to matrix help center.
Here as number og unknown variables are only 2 , solve it directly like , solve two equations and get value of X and y , now if check if those values satisfy third equation or not...
x-y=2 and x+3y=3 gives y=1/4 x=9/4
put in x+5y=-1 .....don't satisfy then No solution satisfy then unique solution..
if number of linearly independent equations less than number of unknown variables => infinite solutions...