\(\left(x-\frac{2}{9}\right)^3=\left(\frac{2}{3}\right)^6=\left(\frac{y}{3}\right)^2\)
\(\Rightarrow\left(\frac{9x-2}{9}\right)^3=\left(\frac{4}{9}\right)^3=\left(\frac{y}{3}\right)^2\)
\(\Rightarrow9x-2=4\)
\(\Rightarrow x=\frac{6}{9}=\frac{2}{3}\)
Xét \(\left(x-\frac{2}{9}\right)^3=\left(\frac{y}{3}\right)^2\)
\(\Rightarrow\frac{4^3}{9^3}=\frac{y^2}{9}\)
\(\Rightarrow4^3=y^2.9^2\)
\(\Rightarrow y^2=\frac{64}{81}\Rightarrow y=\frac{8}{9}\)
\(\left(x-\frac{2}{9}\right)^3=\left(\frac{2}{3}\right)^6\)
\(\Rightarrow\left(x-\frac{2}{9}\right)^3=\left[\left(\frac{2}{3}\right)^2\right]^3\)
\(\Rightarrow x-\frac{2}{9}=\frac{4}{9}\)
\(\Rightarrow x=\frac{4}{9}+\frac{2}{9}\)
\(\Rightarrow x=\frac{6}{9}=\frac{2}{3}\)
\(\left(\frac{y}{3}\right)^2=\left(\frac{2}{3}\right)^6\)
\(\Rightarrow\left(\frac{y}{3}\right)^2=\left[\left(\frac{2}{3}\right)^3\right]^2\)
\(\Rightarrow\frac{y}{3}=\frac{8}{27}\)
\(\Rightarrow y=\frac{8.3}{27}\)
\(\Rightarrow y=\frac{8}{9}\)
Vậy \(x=\frac{2}{3};y=\frac{8}{9}\)
mình muốn hỏi tại sao 4^3/9^3=y^2/9
lại suy ra:4^3=y^2.9^2
