Question

[Edogawa Conan]

Giups mk với: chiều mk nộp bài rồi!

https://olm.vn//hoi-dap/question/1280784.html?auto=1

Answer 1

[Nguyễn Minh Huyền]

Có đáp án rồi thây

Answer 2

[Trần Minh Hoàng]

\(A=3^{-2}.\left[\left(\dfrac{2}{3}\right)^7+\left(\dfrac{2}{3}\right)^7+...+\left(\dfrac{2}{3}\right)^7\right]\) (có 7 số hạng \(\left(\dfrac{2}{3}\right)^7\))

\(=\dfrac{1}{3^2}.7.\dfrac{2^7}{3^7}\)

\(=\dfrac{7.2^7}{3^9}\)

\(=\dfrac{\dfrac{7}{4}.2^9}{3^9}\)

\(=\left(\sqrt[9]{\dfrac{7}{4}}\right)^9.\left(\dfrac{2}{3}\right)^9\)

\(=\left(\sqrt[9]{\dfrac{7}{4}}.\dfrac{2}{3}\right)^9\)

Mình làm ko chắc chắn lắm