Question

г пж срочно !!!!!?!!!

Answer 1

...=2/3
1) 4 2/5-2 3/4+7 7/15-8 7/60=4 24/60-2 45/60+7 28/60-8 7/60 =1
2) 7 1/4-5 3/4=1 2/4=1 1/2
3) 1/(1 1/2)=1*2/3=2/3