Question

1 –.................... =3/7​

Answer 1

let the answer be x

1-x=3/7

x=3/7+1

x=3/7+7/7

x=10/7

Answer 2

$let \: \: missing \: \: number \: \: be \: \: x \\ \\ = 1 - x = \frac{3}{7} \\ \\ = x = 1 - \frac{3}{7} \\ \\ = > x = \frac{7 - 3}{7} \\ \\ = > x = \frac{4}{7}$