\[|3x + 4| = |4x + 3|\]
\[3x + 4 = 4x + 3\]
\[4x - 3x = 4 - 3\]
\[x = 1.\]
\[3x + 4 = - (4x + 3)\]
\[3x + 4 = - 4x - 3\]
\[3x + 4x = - 3 - 4\]
\[7x = - 7\]
\[x = - 1\]
\[Ответ:1;\ - 1.\]