Question

efetue:

(-2/5)(-7/8)(+10/7)=

(-2/3)(+4/6)(-9/8)(+1/8)=

(-1/5)(-2,3)=

(+5/8)(+1,2)=

(-6/7)(28/18)(-3/7)(-0,4)=​

Answer 1

Resposta:

Explicação passo a passo:

B) $\left(-\frac{2}{5}\right)\left(-\frac{7}{8}\right)\left(\frac{10}{7}\right)$

$=\frac{2}{5}\cdot \frac{7}{8}\cdot \frac{10}{7}$

$=\frac{2\cdot \:7\cdot \:10}{5\cdot \:8\cdot \:7}$

$=\frac{2\cdot \:10}{5\cdot \:8}$

$=\frac{20}{40}$

$=\frac{1}{2}$

C) $\left(-\frac{2}{3}\right)\left(\frac{4}{6}\right)\left(-\frac{9}{8}\right)\left(\frac{1}{8}\right)$

$=\frac{2}{3}\cdot \frac{4}{6}\cdot \frac{9}{8}\cdot \frac{1}{8}$

$=\frac{2}{3}\cdot \frac{2}{3}\cdot \frac{9}{8}\cdot \frac{1}{8}$

$=\frac{2\cdot \:2\cdot \:9\cdot \:1}{3\cdot \:3\cdot \:8\cdot \:8}$

$=\frac{36}{3\cdot \:3\cdot \:8\cdot \:8}$

$=\frac{36}{576}$

$=\frac{1}{16}$

D) $\left(-\frac{1}{5}\right)\begin{pmatrix}-2&3\end{pmatrix}$

$=\begin{pmatrix}\left(-\frac{1}{5}\right)\left(-2\right)&\left(-\frac{1}{5}\right)\cdot \:3\end{pmatrix}$

$=\begin{pmatrix}\frac{2}{5}&-\frac{3}{5}\end{pmatrix}$

E) $\left(\frac{5}{8}\right)\left(1.2\right)$

$=\frac{5}{8}\cdot \:1.2$

$=\frac{5\cdot \:1.2}{8}$

$=\frac{6}{8}$

$=\frac{3}{4}$

$=0.75$

F) $\left(-\frac{6}{7}\right)\left(\frac{28}{18}\right)\left(-\frac{3}{7}\right)\begin{pmatrix}-0&4\end{pmatrix}$

$=\begin{pmatrix}\left(-\frac{6}{7}\right)\frac{28}{18}\left(-\frac{3}{7}\right)\left(-0\right)&\left(-\frac{6}{7}\right)\frac{28}{18}\left(-\frac{3}{7}\right)\cdot \:4\end{pmatrix}$

$=\begin{pmatrix}0&\frac{16}{7}\end{pmatrix}$

Espero ter ajudado, poderia marcar como melhor resposta? Agradeço :))