Bài 2:
a) x + $\frac{2}{7}$ = $\frac{3}{14}$
x = $\frac{3}{14}$- $\frac{2}{7}$ = $\frac{3}{14}$ - $\frac{4}{14}$
x = $\frac{-1}{14}$
b) x - $\frac{4}{15}$ = $\frac{3}{10}$
x = $\frac{3}{10}$ + $\frac{4}{15}$ = $\frac{9}{30}$ + $\frac{8}{30}$
x = $\frac{17}{30}$
c) $\frac{-3}{11}$ - x = $\frac{-5}{22}$
x = $\frac{-3}{11}$ - $\frac{-5}{22}$ =$\frac{-6}{22}$ - $\frac{-5}{22}$
x = $\frac{-1}{22}$
d) $\frac{7 }{20}$ - ($\frac{2}{5}$ + x) = $\frac{1}{6}$
$\frac{2}{5}$+x = $\frac{7}{20}$ - $\frac{1}{6}$ = $\frac{21}{60}$- $\frac{10}{60}$
$\frac{2}{5}$+x = $\frac{11}{60}$
x = $\frac{11}{60}$ - $\frac{2}{5}$ = $\frac{11}{60}$ - $\frac{24}{60}$
x = $\frac{-13}{60}$
cho mik xin 5* và ctlhn
@chúc bn hok tốt
