Question 29801
multiply top equation by 4 to give 2x + 8y = 36.


The 2 equations are therefore:

2x + 8y = 36
2x - y  = 18


Subtract them, leaving us with 9y = 18. So y = 18/9 --> y = 2


Put this into either equation:
2x-y = 18
2x-(2) = 18
2x-2 = 18
2x = 20
x = 20/2
x = 10


Put both in the other equation to check your answer is correct:
x/2 + 2y = 9
10/2 + 2(2)
5 + 4
9 --> correct!


jon.