4 4/15 +(5 1/12 - 3 4/12)

4 4/15+(5 1/12-3 4/12)=4 4/15+(4 13/12-3 4/12)=4 4/15+1 9/12=4 4/15+1 3/4=
=64/15+7/4=256/60+105/60=361/60=6 1/60

1)51/12-34/12=17/12
2)44/15+17/12=88/60+85/60=173/60= 2(Целое число) 53/60(дробная часть)
как-то так...