\[(2x + 1)^{2} - 4x^{2} = 7\]
\[4x^{2} + 4x + 1 - 4x^{2} = 7\]
\[4x = 6\]
\[x = \frac{6}{4} = \frac{3}{2}\]
\[x = 1,5.\]