Answer: x=10
Explanation:
f(x)=2 is the same things as y=2. Since we know that y=2, you can plug that in to solve for x.
 [plug in y=2]
 [plug in y=2]
 [multiply both sides by x-2]
 [multiply both sides by x-2]
 [distribute]
 [distribute]
 [subtract both sides by x]
 [subtract both sides by x]
 [add both sides by 4]
 [add both sides by 4]

Now after we have plugged in y=2, we know that x=10.