(x + 4) / (3x) - 5 / (2x)
= 2 (x + 4) / (6x) - 15 / (6x) ……… multiply the first fraction by 3/3 and the second by 2/2 to get a 6 in both denominators
= (2 (x + 4) - 15) / (6x) ……… combine the fractions
= (2x - 7) / (6x) ……… simplify the numerator
so a = 2, b = -7, and c = 6.