When you cannot simplify it further. The terms have no common factor besides 1 and A plus C does not have two numbers that multiply to the total and equal C.
12(x-3) + 18 = 4(2x-3)
12x-36+18 = 8x-12
12x -18 = 8x-12
12x-8x = -12 + 18
4x = 6
x = 6/4 or 3/2
one solution A
The actual wingspan of the airplane would be 504 which isn't an answer but maybe you just typed A. in incorrectly <span />
