Question 88728
For the above problems you first assume values ....,-2,-1,0,1,2.... for x. Substitute all the values one by on in the first equation and then in the second equation. You will get corresponding y values. Now you got two set of values. Then plot those points in graph a usual you will get proper solution.
For eg. consider the 2nd problme 4x-y = 6 , 3x+y=1
                               i.e, y=4x-6 , y=1-3x
If we take x=0 then y=-6 and y=1. So we get 2 sets of values (0,-6) and (0,1)
           x=1 then y=-2 and y=-2. So we get (1,-2) and (1,-2) 
           x=-1 then y=-10 & y=4 . So (-1,-10) & (-1,4) Proceeding like this we get one set as (-1,-11),(0,-6),(1,-2),and so on.and (-1,4), (0,1), (1,-2) and so on. Plot them in graph you will get an intersecting point and that is the value of x and y.