1/2 = 5/10 = 50/100 = 500/1000 = 0,5
2/5 = 4/10 = 40/100 = 400/1000 = 0,4
7/5 = 14/10 = 140/100 = 1400/1000 = 1,4
4/5 = 8/10 = 80/100 = 800/1000= 0,8
А)-1,3;0;0,3;3; 4,2
б)-3/4;-5/6;0;1/2;5/1
3.6-3.5=0.1
7.2-6.9=0.3
12.7+43.3=46
424+26=450
25*8=200
200-4=196
196*90=17640
2*450=900
17640+900=18540