Question

so sánh : -121212/232323 và 4343/-5454

 

Answer 1

\(\dfrac{121212}{232323}=\dfrac{12x10101}{23x10101}=\dfrac{12}{23}=\dfrac{12.54}{23.54}=\dfrac{648}{1242}\)

\(\dfrac{4343}{5454}=\dfrac{43x101}{54x101}=\dfrac{43}{54}=\dfrac{43.23}{23.54}=\dfrac{989}{1242}\)

mà \(\dfrac{989}{1242}>\dfrac{648}{1242}\)

Nên \(\dfrac{121212}{232323}< \dfrac{4343}{5454}\)

\(\Rightarrow-\dfrac{121212}{232323}>-\dfrac{4343}{5454}\)

\(\Rightarrow\dfrac{-121212}{232323}>\dfrac{4343}{-5454}\)

 

Answer 2

Đính chính, có thể so sánh cách 2 nhanh hơn.

...\(\dfrac{12}{23}< \dfrac{12+31}{23+31}=\dfrac{43}{54}\)

\(\Rightarrow\dfrac{121212}{232323}< \dfrac{4343}{5454}\)

\(...\Rightarrow\dfrac{-121212}{232323}>\dfrac{4343}{-5454}\)