Bài 1
a) $\frac{-4}{11}$+$\frac{5}{6}$+$\frac{7}{11}$-$\frac{5}{6}$
<=> ($\frac{-4}{11}$+$\frac{7}{11}$)+($\frac{5}{6}$-$\frac{5}{6}$)
<=> $\frac{3}{11}$+0
<=> $\frac{3}{11}$
Vậy $\frac{-4}{11}$+$\frac{5}{6}$+$\frac{7}{11}$-$\frac{5}{6}$=$\frac{3}{11}$
b) $\frac{-5}{6}$ . $\frac{7}{13}$+$\frac{19}{13}$:$\frac{6}{-5}$+$\frac{2}{5}$
<=> $\frac{-5}{6}$ . $\frac{7}{13}$+$\frac{19}{13}$ . $\frac{-5}{6}$+$\frac{2}{5}$
<=> $\frac{-5}{6}$ . ($\frac{7}{13}$+$\frac{19}{13}$)+$\frac{2}{5}$
<=> $\frac{-5}{6}$ . 2+$\frac{2}{5}$
<=> $\frac{-10}{6}$+$\frac{2}{5}$
<=> $\frac{-50}{30}$+$\frac{12}{30}$
<=> $\frac{-38}{30}$
Vậy $\frac{-5}{6}$ . $\frac{7}{13}$+$\frac{19}{13}$:$\frac{6}{-5}$+$\frac{2}{5}$= $\frac{-38}{30}$
c) Vì ko ghi đc 1/1/2 nên minh ghi là $\frac{3}{2}$ nhé.
$\frac{3}{7}$ . (-0,5+$\frac{3}{2}$)-$\frac{2}{7}$:25%
<=> $\frac{3}{7}$ . ($\frac{-1}{2}$+$\frac{3}{2}$)-$\frac{2}{7}$:25%
<=> $\frac{3}{7}$ . 1-$\frac{8}{7}$
<=> $\frac{3}{7}$-$\frac{8}{7}$
<=> $\frac{-5}{7}$
Vậy $\frac{3}{7}$ . (-0,5+$\frac{3}{2}$)-$\frac{2}{7}$:25% = $\frac{-5}{7}$
