Bài 1:
$\dfrac{1}{-3}=\dfrac{-1}{3}$
$\dfrac{12}{-16}=\dfrac{-3}{4}$
$\dfrac{-70}{-10}=7$
$\dfrac{-12}{-18}=\dfrac{2}{3}$
$\dfrac{0}{-34}=0$
$\dfrac{22}{55}=\dfrac{2}{5}$
$\dfrac{-63}{81}=\dfrac{-7}{9}$
Bài 2:
$\dfrac{4.7.22}{33.14}$
$=\dfrac{4.7.2.11}{3.11.2.7}$
$=\dfrac{4}{3}$
$\dfrac{84.45}{49.54}$
$=\dfrac{2.2.7.3.9.5}{7.7.9.2.3}$
$=\dfrac{2.5}{7}$
$=\dfrac{10}{7}$
$\dfrac{9.6-9.2}{18}$
$=\dfrac{3.3.(6-2)}{2.3.3}$
$=\dfrac{3.3.2.2}{2.3.3}$
$=2$.