Question

efectuati urmatoarele inmultiri: -5/4x8/13
-7/3x(-25/28)
3/28x(-7/5)
20/49x(-14/5)
vă roggg urgent!!

Answer 1

$-\frac{5}{4}\cdot \frac{8}{13}=-\frac{5\cdot \:2}{1\cdot \:13}=-\frac{10}{1\cdot \:13}=-\frac{10}{13}$

$-\frac{7}{3}\left(-\frac{25}{28}\right)=\frac{1}{3}\cdot \frac{25}{4}=\frac{25}{3\cdot \:4}=\frac{25}{12}$

$\frac{3}{28}\left(-\frac{7}{5}\right)=-\frac{3}{28}\cdot \frac{7}{5}=-\frac{3\cdot \:1}{4\cdot \:5}=-\frac{3}{20}$

$\frac{20}{49}\left(-\frac{14}{5}\right)=-\frac{20}{49}\cdot \frac{14}{5}=-\frac{280}{49\cdot \:5}=-\frac{280}{245}=-\frac{8}{7}$