Найдите значение выражения, за ранее сократив дроби: 1) 25/80 + 45/60; 3)

1) 25/80 + 45/60 = 5/16 + 3/4 = (5*1+3*4)/16 = (5+12)/16 = 17/16;
2) 20/45 + 26/54 = 4/9 + 13/27 = (4*3+13*1)/27 = (12+13)/27 = 25/27;
3) 36/300+12/40-350/1000=9/75+3/10-7/20=(3*4+3*10-7*5)100=(12+30-35)/100=7/100;
4) 14/24-39/90+15/100=7/12-13/30+3/20=(7*5-13*2+3*3)/60=(35-26+9)/60=18/60=3/20;
5) 42/120+20/32-28/160=7/20+5/8-7/40=(7*2+5*5-7*1)/40=(14+25-7)/40=32/40=4/5;
6) 45/72-33/144-20/64=5/8-11/48-5/16=(5*6-11*1-5*3)/48=(30-11-15)/48=4/48=1/12.