[Risolto] N. 495

$ \big[\big(-4 + \frac{2}{3}\big) : \big(\frac{3}{2}-\frac{2}{3}\big)-\big(-1+\frac{6}{5}\big)\big]×\big(-\frac{1}{3}+\frac{4}{7}\big)$ =

= $ \big[\big(\frac{-12+2}{3}\big) : \big(\frac{9-4}{6}\big)-\big(\frac{-5+6}{5}\big)\big]×\big(\frac{-7+12}{21}\big)$ =

= $ \big[-\frac{10}{3} : \frac{5}{6}-\frac{1}{5}\big]×\frac{5}{21}$ =

= $ \big[-\frac{10}{3}×\frac{6}{5}-\frac{1}{5}\big]×\frac{5}{21}$ =

= $ \big[-\frac{2}{1}×\frac{2}{1}-\frac{1}{5}\big]×\frac{5}{21}$ =

= $ \big[-4-\frac{1}{5}\big]×\frac{5}{21}$ =

= $\big[\frac{-20-1}{5}\big]×\frac{5}{21}$ =

= $ -\frac{21}{5}×\frac{5}{21}$ =

= $ -\frac{1}{1}×\frac{1}{1}$ =

= $-1$