Question

giúp em với ạ

Answer 1

\(7a,\\ 2\dfrac{3}{5}=2,6\\ Vì:2,4< 2,6\Rightarrow2,4< 2\dfrac{3}{5}\\ 7b\\ -\dfrac{2}{5}=-0,4\\ Vì:-0,12>-0,4\Rightarrow-0,12>\dfrac{-2}{5}\\ c,\dfrac{-2}{7}=\dfrac{-2.10}{7.10}=\dfrac{-20}{70}\\ -0,3=\dfrac{-3.7}{10.7}=\dfrac{-21}{70}\\ Vì:\dfrac{-20}{70}>\dfrac{-21}{70}\Rightarrow-\dfrac{2}{7}>-0,3\)

Answer 2

8) a) Sắp xếp theo thứ tự tăng dần là:

\(-0,5;-\dfrac{3}{7};\dfrac{2}{7};0,4\)

b) Sắp xếp theo thứ tự giảm dần:

\(-0,75;-\dfrac{5}{6};-1;-4,5\)

Answer 3

7) a) \(2,4=\dfrac{24}{10}=\dfrac{12}{5}\)

\(2\dfrac{3}{5}=\dfrac{13}{5}\)

Mà: \(13>12\Rightarrow\dfrac{13}{5}>\dfrac{12}{5}\)

\(\Rightarrow2,4>2\dfrac{3}{5}\)

b) \(-0,12=-\dfrac{12}{100}=-\dfrac{3}{25}\)

\(-\dfrac{2}{5}=-\dfrac{10}{25}\)

Mà: \(-3>-10\Rightarrow-\dfrac{3}{25}>\dfrac{-10}{25}\Rightarrow-0,12>-\dfrac{2}{5}\)

c) \(\dfrac{-2}{7}=\dfrac{-20}{70}\)

\(-0,3=-\dfrac{3}{10}=-\dfrac{21}{70}\)

Mà: \(-20>-21\Rightarrow-\dfrac{20}{70}>-\dfrac{21}{70}\Rightarrow-\dfrac{2}{7}>-0,3\)