\(\left(x-3\right)^4=81\)
\(\left(x-3\right)^4=3^4\)
\(\Rightarrow x-3=3\)
\(\Rightarrow x=3+3\)
\(\Rightarrow x=6\)
**** Nguyen Thi Trang Anh
\(\left(x-3\right)^4=81\)
\(=>x-3=3\) hoặc \(x-3=-3\)
x = 3 + 3 x = -3 + 3
x =6 x = 0