Question

Tìm x, biết

(2x+1)³ = 343

Answer 1

\(\left(2x+1\right)^3=343\)

\(\left(2x+1\right)^3=7^3\)

\(\Rightarrow2x+1=7\)

\(2x=7-1\)

\(2x=6\)

\(x=6:2\)

\(x=3\)

Vậy x = 3

Answer 2

Ta có: (2x + 1)³ = 343

     \(\Leftrightarrow\)(2x + 1)³ = 7³

    \(\Leftrightarrow\)2x + 1 = 7

    \(\Leftrightarrow\)2x = 7 - 1 = 6

    \(\Leftrightarrow\)x = 6: 2 = 3

Vay x = 3

Answer 3

ta có 

(2x+1)^3=343

<=>(2x+1)^3=7^3

=>2x+1=7

=>x=4