How does the inverse of f(x)= .5x - 1 = 2+2x? show steps

Re-write f(x) as y and to find a inverse of a function you swap the x and y values

f(x) = 0.5 x - 1

Swap x and y values

y  = 0.5x - 1

x = 0.5 y - 1 
+1          +1

x + 1 = 0.5y 

y = 2 + 2x

Rewrite the notation..

f(x) ^-1 =  2 + 2x 

F(x)=0.5x-1=2+2x
f(x)=0.5x-1
y=0.5x-1
f^-1(x)=x=0.5y-1
x+1=0.5y
(2)(x+1)=y
2x+2=y

I'm sure the answer is a

B. 2 1/2 feet. multiply 2.5 inches by 12 to get thirty inches then divide by 12 to get 2.5 feet