First we have the given function, so y = 6 - x/2
Then, the first step to find the inverse is switching places of x and y, so x = 6 - y/2
Then, we need to isolate y, so first we have y/2 = 6 - x
Now, multiplying the equation by 2, we have y = 12 - 2x
And finally, switching y by f^-1(x), we have f^-1(x) = 12 - 2x
