(уравнение)
3x=5
0,7x=-2
-2,1x=3,6

1)x=5/3

2)x=-2/0.7 x=-20/7

3)x=-3.6/2.1=-36/21=-12/7

Выбираем лучшее решение!

x=5:3                          x=-2:0.7                            x=3.6:2.1

x=5|3                          x=-20:7                              x=36:21

x=1,66                   x=-2,86                            x=1,71