Question 31150
x/2+2y=9  
2x-y=18 multiply by 2 
4x-2y=36
x/2+2y=9 adding these two equatons 
4 1/2x=45 or x=10
substituting 10 for x in the first equation we get 
10/2+2y=9 or 5+2y=9 or 2y=4 or y=2