Đáp án:
a.$\dfrac4{-3}+\dfrac{-22}{5}=\dfrac{-86}{15}$
b.$\dfrac{-5}{-6}+\dfrac7{-8}=\dfrac{-1}{24}$
Giải thích các bước giải:
a.$\dfrac4{-3}+\dfrac{-22}{5}$
$=-\dfrac{4}{3}-\dfrac{22}{5}$
$=-\dfrac{20}{15}-\dfrac{66}{15}$
$=\dfrac{-20-66}{15}$
$=\dfrac{-86}{15}$
b.$\dfrac{-5}{-6}+\dfrac7{-8}$
$=\dfrac{5}{6}-\dfrac{7}{8}$
$=\dfrac{20}{24}-\dfrac{21}{24}$
$=\dfrac{20-21}{24}$
$=\dfrac{-1}{24}$