x / [ x + 2 ] + 12 = [ x + 3 ] / ( 2 [ x + 2 ] ) simplify
[ x + 12 (x + 2) ] / [ x + 2] = [ x + 3 ] / ( 2 [ x + 2] )
x + 12x + 24 = [ x + 3 ] / 2
13x + 24 = [ x + 3 ] / 2 cross-multiply
26x + 48 = x + 3 simplify
25x = - 45
x = - 45 / 25 = - 9 / 5 = original numerator