You have to add the whole numbers, which is 5 + 2 = 7. Then you add the fractions. In order to do that, you have to convert 4/9 to X/36 so 15/36 and 4/9 have the same denominator. In this case, 9 is a factor of 36, so you can multiply 4/9 by 4/4 (which is like multiplying by one). The result is 16/36. Now add the numerators 15 + 16 = 31. Denominator remains 36 because you do not change it when you add fractions.
The result therefore is 7 and 31/36.