Question

при каком х верно равенсвтве21/21=40/х-9?

Answer 1

21/21=40/4-9
1=10-9
1=1
x=4

Answer 2

Что? O_o

Answer 3

21/21 = 40/x-9
1 = 40/x-9
x-9 = 40
x = 49

Answer 4

40 подели на 49 -_-