Answer:
y = 9x
Step-by-step explanation:
If you plug in the point into each equation, you get:
y = 1/9x
18 = 1/9 * 2
18 = 2/9
not true
y = 18x
18 = 18 * 2
18 = 36
not true
y = 9x
18 = 9 * 2
18 = 18
true, so this is the answer
y = 2x
18 = 2 * 2
18 = 4
not true
