\(\frac{16}{81}=\left(\frac{-4}{9}\right)^2=\left(\frac{4^2}{3^2}\right)=\left(\frac{\left(-4\right)^2}{\left(-3\right)^2}\right)=....\)
\(\frac{16}{81}=\left(\frac{4}{9}\right)^2\)
\(\frac{16}{81}=\left(\frac{-4}{9}\right)^2=\left(\frac{4^2}{9^2}\right)=\left(\frac{\left(-4\right)^2}{\left(-9\right)^2}\right)=....\)
Mình làm lại nhé, phần trên kia sai đó