(2x + 1)3 = 343
=> (2x + 1)3 = 73
=> 2x + 1 = 7
=> 2x = 6
=> x = 3
\(\left(2x+1\right)^3=343\)
\(\Leftrightarrow\left(2x+1\right)^3=7^3\)
\(\Leftrightarrow2x+1=7\)
\(\Leftrightarrow2x=6\)
\(\Leftrightarrow x=3\)
\(\left(2x+1\right)^3=343\Leftrightarrow\left(2x+1\right)^3=7^3\)
\(\Leftrightarrow2x+1=7\Leftrightarrow x=3\)
(2.x+1)3=343
\(\Leftrightarrow\) ( 2x +1) = 73
\(\Leftrightarrow\) 2x + 1 = 7
\(\Leftrightarrow\)2x = 6
\(\Rightarrow\) x = 3
Vậy , x=3