Question

resolva as equações 3x-21=0

Answer 1

3x-21=0
3x=21
x=21/3
x=7

Answer 2

3x - 21 = 0 ~~passo o 21~~
3x = 21 ~~passo o 3 dividindo~~
x = 21/3
x = 7 

S = {7}