Question

Ae giúp mình câu c g d h

Answer 1

c) \(\dfrac{4}{5}+\dfrac{4}{-18}=\dfrac{4}{5}+\dfrac{-4}{18}=\dfrac{72}{90}+\dfrac{-20}{90}=\dfrac{52}{45}=\dfrac{26}{45}\)

 

Answer 2

Giải:

c) \(\dfrac{4}{5}+\dfrac{4}{-18}=\dfrac{4}{5}+\dfrac{-2}{9}=\dfrac{36}{45}+\dfrac{-10}{45}=\dfrac{36+\left(-10\right)}{45}=\dfrac{26}{45}\) 

d) \(\dfrac{-18}{24}+\dfrac{15}{-21}=\dfrac{-3}{4}+\dfrac{-5}{7}=\dfrac{-21}{28}+\dfrac{-20}{28}=\dfrac{-21+\left(-20\right)}{28}=\dfrac{-41}{28}\) 

g) \(\dfrac{3}{5}-\dfrac{5}{6}=\dfrac{18}{30}-\dfrac{25}{30}=\dfrac{18-25}{30}=\dfrac{-7}{30}\) 

h) \(\dfrac{-5}{9}-\dfrac{-5}{12}=\dfrac{-20}{36}-\dfrac{-15}{36}=\dfrac{-20-\left(-15\right)}{36}=\dfrac{-5}{36}\)