Solution:
The given equation is:

A: Taking , x=1
L H S = 9 × 1 + 49 = 9 + 49= 58
R H S : 
L H S ≠ R H S
B: Taking x=3
L H S = 9 × 3 + 49=27 + 49=76
R HS = 
L H S ≠ R H S
C: Taking x=5
L H S = 9 × 5 + 49
= 45 + 49
= 94
R H S:

L H S ≠ R H S
(D)
when , x= 8
L H S
9 × 8 + 49
= 72 + 49
= 121
R HS:

L H S ≠ R H S
This should be the right answer though. If you go to desmos.com and type in the equations it gives you the answer.
Hope that helps :)
Let
x = number of common cars
y = number of suvs
we can write the following system of equations
x-y = 12
x = 1.429y
Solving the system we have
x-y = 12
1.429y-y = 12
and (1,429-1) = 12
y = (12) / (1,429-1) = 27.97202797
then,
x = 1429 * (27.97202797)
x = 39.97202797
answer
The number of suvs in the parking lot is 28
F(x) = (1/9 x) - 2
y = (1/9 x) - 2
(1/9 x) = y + 2
x = 9(y + 2) = 9y + 18
f^-1(x) = 9x + 18