Answer:
NP (Not possible)
Explanation:
When you find 'X', by inserting '6x-3' into the 'Y', you get:
18x - 3(6x-3) = 9
distribute:
18x -18x + 9 = 9
Subtract 9 from 9 = 0
Add like numbers (the x's), and it equals 0
0=0
You can't find x, rendering the equation 'NP'
Hopefully this answer is right and an option :)