3/5х4/9+1 1/3=12/45+4/3=72/45=8/5
1 1/4х2/5-1/3=1/2-1/3=1/6
3/8:1/2+3 1/4=6/8+13/4=32/8=4
5/6:1/3+1 3/8=15/6+11/8=93/24=31/8
1 2/5:5/7+3/8=7/5х7/5+3/8=49/25+3/8=467/200
2 1/3:1 5/9-5/6=7/3х9/14-5/6=63/42-5/6=28/42=2/3
350:7+40=90
70*3+320=530
900-60*5=600
680-240:4=620
1)(-6+(-19))+15=-5
2)-3.6+((-7.2)+4.5)=-6.3
3)(-1.4+(-1.8))+(-5.2+8.1)=-0.3