Question

x+7/21=4/7 determine o valor da incógnita

Answer 1

x+7/21=4dv7
x+1/3=4dv7
x+1/3=4/7
x=4/7-1/3
x=3.4-7.1/21
x=3.4-7/21
x=12-7/21
x=5/21

Answer 2

x=4/7_7/21

encontra o mmc, então x=12_7/21
x=5/21