[Risolto] Es. N 678

678)

$\frac{-\frac{1}{2}·\big[\big(\frac{1}{6}+1+\frac{1}{12}\big)^2 : \big(2-\frac{9}{4}\big)^2+\frac{4}{3} : \frac{4}{9} -8\big]}{8·\big(1-\frac{3}{4}\big)-\big(\frac{2}{3}-\frac{1}{4}\big) : \big(\frac{5}{12}-\frac{5}{18}\big)}·\frac{1}{5}$ =

$\frac{-\frac{1}{2}·\big[\big(\frac{2+12+1}{12}\big)^2 : \big(\frac{8-9}{4}\big)^2+\frac{4}{3}· \frac{9}{4} -8\big]}{8·\big(\frac{4-3}{4}\big)-\big(\frac{8-3}{12}\big) : \big(\frac{15-10}{36}\big)}·\frac{1}{5}$ =

$\frac{-\frac{1}{2}·\big[\big(\frac{15}{12}\big)^2 : \big(-\frac{1}{4}\big)^2+\frac{1}{1}· \frac{3}{1} -8\big]}{8·\frac{1}{4}-\frac{5}{12} : \frac{5}{36}}·\frac{1}{5}$ =

$\frac{-\frac{1}{2}·\big[\big(\frac{5}{4}\big)^2 : \frac{1}{16}+3 -8\big]}{2-\frac{5}{12}· \frac{36}{5}}·\frac{1}{5}$ =

$\frac{-\frac{1}{2}·\big[\frac{25}{16}·16 -5\big]}{2-\frac{1}{1}· \frac{3}{1}}·\frac{1}{5}$ =

$\frac{-\frac{1}{2}·\big[25 -5\big]}{2-3}·\frac{1}{5}$ =

$\frac{-\frac{1}{2}·20}{-1}·\frac{1}{5}$ =

$\frac{-10}{-1}·\frac{1}{5}$ =

$10·\frac{1}{5} = 2$