3х-5-7х+3=-4х-2 или -2(2х+1)
7 5/10:3/8=75/10*8/3=200/10
4 2/3*6/10=28/10
200/10+28/10=228/10
228/10:1 9/10=228/10*10/19=12
2 5/10:1 3/7=25/10*7/10=175/100
175/100+5 25/100=700/100=7
7:2 1/3=7*3/7=3
12:3=4
2 2/3*15/100=120/300=12/30
12/30:6/10=2/3
5/10-1/12=25/60=5/12
5/12*8/10=8/24=1/3
2/3:1/3=2
4+2=6