10,5-4x=2
4x=10,5-2
4x=8,5
x=8,5:4
x=2,125
__________
10,5-2,125=2
20x+15,4=21
20x=21-15,4
20x=5,6
x=5,6:20
x=0,28
___________
0,28+15,4=21
1)31/7=4,42(4,4)
2)4,4*7,425=32,67(32,7)
3)-6,425*31=-199,175(-199,2)
4)-199,2/7=-28,45(-28,5)
5)32,7+-28,5=4,2
1)12/10 = 6/5 = 1 1/5
2) 58/10 = 29/5 = 5 4/5
3) 1925/100 = 385/20 = 77/4 = 19 1/4
4) 198/10 = 99/5 =19 4/5
5) 47200/1000 = 944/20 = 236/5 = 47 1/5