Please help me write this as a single fraction? Sorry my addition/equal key does not work

- 3a-7b/2a plus 5a-4b/3a plus 3.

-(3a-7b)/(2a) + (5a-4b)/(3a) + 3

The common denominator is (2a)(3a), so we have for the numerator

-(3a-7b)(3a) + (5a-4b)(2a) + 3(2a)(3a)
= 19a^2+13ab

so, our final fraction is

(19a^2+13ab)/6a^2 = (19a+13b)/(6a)