this is on the Barron's SAT Math IIC Book page 41.

Which of the following equations can represent the inverse of the attachment? (the line on the attachment is y=f(x)

a) y=-2x+1

b) y=2x+1

c) 1/2x+1

d) y=1/2x-1

e) y=1/2x-(1/2)

I know that inverse means that for example the inverse of function y=2x is y=x/2 but how do you do this problem?

Thanks in advance