Explicație pas cu pas:
[tex]21 \frac{1}{5} \div (7 \frac{1}{5} - 3 \frac{1}{10} + 6 \frac{1}{2} ) + \frac{2}{3} \times ( \frac{5}{2} - \frac{5}{3} ) \div \frac{1}{27} = 17[/tex]
