Question 5477
3x-2y=11
x-y=4
add y to both sides of the second equation to get
x=y+4
then use Y+4 in the first equation instead of x
3(y+4)-2y=11
3y+12-2y=11
y+12=11
y=-1
then put -1 back into your equation and solve for x:
x-y=4
x-(-1)=4
x+1=4
x=3
the solution is (3,-1)

This will have only one solution because these are two straight lines, and the solution is where these two lines cross.  (straight lines can only cross once).