Respuesta :

Answer:

y = 2x - 18

Step-by-step explanation:

replace the f(x) for y

y = 1/2 x + 9

switch y and x

x = 1/2y + 9

solve for y

subract 9

x - 9 = 1/2y

divide by 1/2 or multiply by the reciprocal (2)

y = 2x -18