$\frac{x}{y}$ $\frac{x}{y}$ $\frac{x}{y}$ Đáp án:
Giải thích các bước giải:
a, $\frac{-5}{2}$ + $\frac{1}{3}$ - $\frac{2}{4}$
= $\frac{-30}{12}$ + $\frac{4}{12}$ - $\frac{6}{12}$
= $\frac{-32}{12}$ = $\frac{-8}{3}$
b, $\frac{1}{7}$ + $\frac{5}{6}$ - $\frac{8}{21}$
= $\frac{6}{42}$ + $\frac{35}{42}$ - $\frac{16}{42}$
= $\frac{25}{42}$
c, $\frac{-8}{14}$ - $\frac{2}{7}$ + $\frac{-5}{2}$
= $\frac{-8}{14}$ - $\frac{4}{14}$ + $\frac{-35}{14}$
= $\frac{-47}{14}$
d, $\frac{-2}{3}$ + $\frac{4}{7}$ - $\frac{5}{-9}$
= $\frac{-42}{63}$ + $\frac{36}{63}$ - $\frac{-35}{63}$
= $\frac{29}{63}$
e, $\frac{-7}{5}$ + $\frac{6}{11}$ +$\frac{7}{5}$ - $\frac{21}{11}$
= ($\frac{-7}{5}$ + $\frac{7}{5}$)+ $\frac{6}{11}$ - $\frac{21}{11}$
= 0 - $\frac{15}{11}$ = $\frac{-15}{11}$
f, $\frac{1}{4}$ + $\frac{11}{13}$ - $\frac{8}{5}$ - $\frac{11}{13}$
=($\frac{11}{13}$- $\frac{11}{13}$ )+ $\frac{1}{4}$ - $\frac{8}{5}$
= 0 + $\frac{5}{20}$ - $\frac{32}{20}$
= $\frac{-27}{20}$
g, $\frac{-1}{5}$ + $\frac{2}{6}$ - $\frac{1}{5}$ - $\frac{15}{9}$
= ($\frac{-1}{5}$ - $\frac{1}{5}$)+$\frac{6}{18}$ - $\frac{30}{18}$
= $\frac{-2}{5}$ - $\frac{24}{18}$
= $\frac{-2}{5}$ - $\frac{4}{3}$
= $\frac{-6}{15}$ - $\frac{20}{15}$ = $\frac{-26}{15}$
h, $\frac{-9}{11}$ + $\frac{-6}{4}$ - $\frac{9}{11}$ + $\frac{30}{6}$
= $\frac{-18}{11}$ + $\frac{-18}{12}$ + $\frac{60}{12}$
= $\frac{-18}{11}$ + $\frac{42}{12}$ = $\frac{-18}{11}$ + $\frac{7}{2}$
= $\frac{-36}{22}$ + $\frac{77}{22}$= $\frac{41}{22}$
