[attach]44886[/attach]

Urgente

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$x : \big(\frac{2}{5}+\frac{3}{13}·\frac{39}{5}\big) = \big(5+\frac{13}{14}-\frac{3}{7}\big) : \big(3-\frac{4}{5}\big)^2$

$x : \big(\frac{2}{5}+\frac{3}{1}·\frac{3}{5}\big) = \big(\frac{70+13-6}{14}\big) : \big(\frac{15-4}{5}\big)^2$

$x : \big(\frac{2}{5}+\frac{9}{5}\big) = \frac{77}{14} : \big(\frac{11}{5}\big)^2$

$x : \frac{11}{5} = \frac{11}{2} : \frac{121}{25}$

$x= \frac{\frac{11}{5}·\frac{11}{2}}{\frac{121}{25}}$

$x= \frac{11}{5}·\frac{11}{2}·\frac{25}{121}$

semplifica in croce la 1° frazione con l'ultima:

$x= \frac{1}{1}·\frac{1}{2}·\frac{5}{11}$

$x=\frac{5}{2}$