Giải đáp án

Trang Nguyễn

a)

$\left(-\frac{3}{7}\right)+\left(\frac{5}{6}-\frac{4}{7}\right)$

$=\left\lbrack\left(-\frac{3}{7}\right)-\frac{4}{7}\right\rbrack+\frac{5}{6}$

$=-1+\frac{5}{6}$

$=-\frac{1}{6}$

b)

$\frac{3}{5}-\left(\frac{2}{3}+\frac{1}{5}\right)$

$=\left(\frac{3}{5}-\frac{1}{5}\right)-\frac{2}{3}$

$=\frac{2}{5}-\frac{2}{3}$

$=-\frac{4}{15}$

c)

$\left\lbrack\left(-\frac{1}{3}\right)+1\right\rbrack-\left(\frac{2}{3}-\frac{1}{5}\right)$

$=\left(-\frac{1}{3}\right)+1-\frac{2}{3}+\frac{1}{5}$

$=\left\lbrack\left(-\frac{1}{3}\right)-\frac{2}{3}\right\rbrack+1+\frac{1}{5}$

$=-1+1+\frac{1}{5}$

$=0+\frac{1}{5}$

$=\frac{1}{5}$

d)

$1\frac{1}{3}+\left(\frac{2}{3}-\frac{3}{4}\right)-\left(0,8+1\frac{1}{5}\right)$

$=1+\frac{1}{3}+\frac{2}{3}-\frac{3}{4}-\left(\frac{4}{5}+1+\frac{1}{5}\right)$

$=1+\frac{3}{3}-\frac{3}{4}-\left(\frac{5}{5}+1\right)$

$=1+1-\frac{3}{4}-\left(1+1\right)$

$=-\frac{3}{4}$.