first write it out:
3y = -1/2x + 2
y = -x + 9
now sub in the y
3(-x+9)= -1/2x + 2
and solve.. [ill do it for you :)]
-3x + 27 = -1/2x + 2
now just simplify
27=2.5x + 2
-2 - 2
25 = 2.5x
25/2.5= 10
10=x... now for the y :/ but dont worry its simple just sub in the x which is 10 to the equation that seems the simplest which is the second one.
y = -(10) + 9
-10 + 9 = -1
x=10 y = -1