Giải câu 6 trang 43 Cánh Diều Toán 6 tập 2.
a) $\frac{4}{7}$ . x - $\frac{2}{3}$ = $\frac{1}{5}$
$\frac{4}{7}$ . x = $\frac{1}{5}$ + $\frac{2}{3}$
$\frac{4}{7}$ . x = $\frac{1 . 3}{5 . 3}$ + $\frac{2 . 5}{3 . 5}$
$\frac{4}{7}$ . x = $\frac{3}{15}$ + $\frac{10}{15}$
$\frac{4}{7}$ . x = $\frac{13}{15}$
x = $\frac{13}{15}$ : $\frac{4}{7}$
x = $\frac{13}{15}$ . $\frac{7}{4}$
x = $\frac{91}{60}$
b) $\frac{4}{5}$ + $\frac{5}{7}$ : x = $\frac{1}{6}$
$\frac{5}{7}$ : x = $\frac{1}{6}$ - $\frac{4}{5}$
$\frac{5}{7}$ : x = $\frac{1 . 5}{6 . 5}$ - $\frac{4 . 6}{5 . 6}$
$\frac{5}{7}$ : x = $\frac{5}{30}$ - $\frac{24 }{30}$
$\frac{5}{7}$ : x = $\frac{- 19}{30}$
x = $\frac{5}{7}$ : $\frac{- 19}{30}$
x = $\frac{5}{7}$ . $\frac{30}{- 19}$
x = $\frac{5 . 30}{7 . (- 19)}$
x = $\frac{- 150}{133}$