3/7-2/21=? Aidez moi svp

Bonsoir

[tex] \frac{3}{7} - \frac{2}{21} \\ = \frac{3 \times 3}{7 \times 3} - \frac{2}{21} = \frac{9}{21} - \frac{7}{21} \\ = \frac{9 - 2}{21} = \frac{7}{21} [/tex]

= 1/3

Bonne soirée