(7/8-3/5)÷(2/3+1/2)×(60÷4целых5/7

1)7/8-3/5=11/40 2)2/3+1/2=7/6 3)60/4 5/7=60/33/7=420/33 4)11/40:7/6=11/40*6/7=33/140 5)33/140*420/33=3

1) 7/8-3/5=35/40-24/40=11/40 2) 2/3+1/2=4/6+3/6=7/6 3) 60÷4целых5/7=60/1÷33/7=60/1×7/33=420/33=140/11 4) 11/40÷7/6=11/40×6/7=66/280=33/140 5) 33/140×140/11=33/11=3/1=3