Question

решите пропорцию: 42 : 4x = 21 : 4

Answer 1

4x=42*4:21
4x=8
x=8:4
x=2

Answer 2

6x=78:9*39

Answer 3

6x=78:39*9

Answer 4

6x=18, x=18:6, x=3

Answer 5

наверно так

Answer 6

спс