a) \(\left(\dfrac{2}{3}\right)^2=\dfrac{2^2}{3^2}=\dfrac{4}{9}\)
\(\left(\dfrac{-2}{3}\right)^2=\dfrac{\left(-2\right)^2}{3^2}=\dfrac{4}{9}\)
Mà: \(\dfrac{4}{9}=\dfrac{4}{9}\Rightarrow\left(\dfrac{2}{3}\right)^2=\left(\dfrac{-2}{3}\right)^2\)
b) \(\left(\dfrac{3}{5}\right)^2=\dfrac{3^2}{5^2}=\dfrac{9}{25}\)
\(\left(-\dfrac{3}{5}\right)^2=\left(\dfrac{-3}{5}\right)^2=\dfrac{\left(-3\right)^2}{5^2}=\dfrac{9}{25}\)
Mà: \(\dfrac{9}{25}=\dfrac{9}{25}\Rightarrow\left(\dfrac{3}{5}\right)^2=\left(-\dfrac{3}{5}\right)^2\)
c) \(\left(-1\dfrac{2}{3}\right)^2=\left(-\dfrac{5}{3}\right)^2=\left(\dfrac{-5}{3}\right)=\dfrac{\left(-5\right)^2}{3^2}=\dfrac{25}{9}\)
\(\left(1\dfrac{2}{3}\right)^2=\left(\dfrac{5}{3}\right)^2=\dfrac{5^2}{3^2}=\dfrac{25}{9}\)
Mà: \(\dfrac{25}{9}=\dfrac{25}{9}\Rightarrow\left(-1\dfrac{2}{3}\right)^2=\left(1\dfrac{2}{3}\right)^2\)
d) \(\left(-0,1\right)^2=\left(-0,1\right)\cdot\left(-0,1\right)=0,01\)
\(\left(0,1\right)^2=0,1\cdot0,1=0,01\)
Mà: \(0,01=0,01\Rightarrow\left(-0,1\right)^2=\left(0,1\right)^2\)
a) (\(\dfrac{2}{3}\))\(^2\)=(\(\dfrac{-2}{3}\))=\(\dfrac{4}{9}\)
b) = nhau và =\(\dfrac{9}{25}\)
c) ---------------=\(\dfrac{5}{9}\)
d)---------------=0,01