Đáp án+Giải thích các bước giải:
c, 2.$\frac{4}{5}$:[($\frac{-5}{2}$+(-2.$\frac{2}{3}$)]
=$\frac{14}{5}$ :[$\frac{-5}{2}$ -$\frac{8}{3}$]
=$\frac{14}{5}$ :$\frac{-31}{6}$
=$\frac{-84}{185}$
d,(-5).$\frac{-6}{13}$.$\frac{-9}{10}$.($\frac{-13}{36}$
=(-5).$\frac{-9}{10}$.$\frac{-6}{13}$.$\frac{-13}{36}$
=$\frac{9}{2}$.$\frac{1}{6}$
=$\frac{3}{4}$
e,($\frac{-1}{3}$+$\frac{3}{11}$):$\frac{2015}{2}$+($\frac{1}{3}$+$\frac{8}{11}$):$\frac{2015}{2}$
=($\frac{-1}{3}$+$\frac{3}{11}$).$\frac{2}{2015}$+($\frac{1}{3}$+$\frac{8}{11}$).$\frac{2}{2015}$
=[($\frac{-1}{3}$+$\frac{3}{11}$)+($\frac{1}{3}$+$\frac{8}{11}$)].$\frac{2}{2015}$
=[($\frac{-1}{3}$+$\frac{1}{3}$+$\frac{3}{11}$+$\frac{8}{11}$].$\frac{2}{2015}$
=[0+1].$\frac{2}{2015}$
=1.$\frac{2}{2015}$
=$\frac{2}{2015}$
f,$\frac{7}{8}$:($\frac{2}{9}$-$\frac{1}{18}$)+$\frac{7}{8}$:($\frac{1}{36}$-$\frac{5}{12}$)
=$\frac{7}{8}$:$\frac{1}{6}$+$\frac{7}{8}$:$\frac{-7}{18}$
=$\frac{21}{4}$+$\frac{-9}{4}$
=3
Chúc bn học tốt!
Xin ctlhn+5sao!
