(7x - 11)3 = 25 . 52 + 200
\(\Rightarrow\) (7x - 11)3 = 32 . 25 + 200
\(\Rightarrow\) (7x - 11)3 = 800 + 200 \(\Rightarrow\) (7x - 11)3 = 1000 \(\Rightarrow\) (7x - 11)3 = 103 \(\Rightarrow\) 7x - 11 = 10 \(\Rightarrow\) 7x = 10 + 11 \(\Rightarrow\) 7x = 21 \(\Rightarrow\) x = 21 : 7 \(\Rightarrow\) x = 3 Vậy: x = 3