Bài 1:
a, x.$\frac{3}{7}$ + $\frac{4}{7}$ = $\frac{-2}{7}$
x.$\frac{3}{7} = $$\frac{-2}{7}$$ - $$\frac{4}{7}$
x.$\frac{3}{7}$= $\frac{-6}{7}$
x = $\frac{-6}{7}$ : $\frac{3}{7}$
x = -2
b, x.($\frac{3}{7}$ - $\frac{-4}{7}$) = $\frac{-2}{7}$
x . 1 = $\frac{-2}{7}$
x = $\frac{-2}{7}$
c, (x - $\frac{3}{-7}$).$\frac{4}{7}$ = $\frac{-2}{7}$
(x - $\frac{3}{-7}$) = $\frac{-2}{7}$ : $\frac{4}{7}$
(x - $\frac{3}{-7}$) = $\frac{-1}{2}$
x - $\frac{3}{-7}$ = $\frac{-1}{2}$ + $\frac{3}{-7}$
x = $\frac{-13}{14}$
Bài 2:
a, $\frac{-4}{3}$ và $\frac{11}{-5}$
$\frac{-4}{3}$ = $\frac{-20}{15}$; $\frac{11}{-5}$ = $\frac{-33}{15}$
⇒ $\frac{-4}{3}$ > $\frac{11}{-5}$
b, $\frac{23}{48}$ và $\frac{19}{36}$
$\frac{23}{48}$ = $\frac{69}{144}$; $\frac{19}{36}$ = $\frac{76}{144}$
⇒ $\frac{23}{48}$ < $\frac{19}{36}$
c, $\frac{56}{51}$ và $\frac{66}{61}$
$\frac{56}{51}$ = $\frac{3416}{3111}$; $\frac{66}{61}$ = $\frac{3366}{3111}$
⇒ $\frac{56}{51}$ < $\frac{66}{61}$
