Răspuns :
[tex] \frac{18}{5} \div \frac{21}{5} = [/tex]
[tex] = \frac{18}{5} \times \frac{5}{21} [/tex]
[tex] = \frac{18}{21} [/tex]
[tex] = \frac{6}{7} [/tex]
[tex] \frac{18}{5} \div \frac{21}{5} = [/tex]
[tex] = \frac{18}{5} \times \frac{5}{21} [/tex]
[tex] = \frac{18}{21} [/tex]
[tex] = \frac{6}{7} [/tex]