\[ -7x - 2 imes 3 - 2 imes (-2x) = 15 \]
\[ -7x - 6 + 4x = 15 \]
\[ (-7x + 4x) - 6 = 15 \]
\[ -3x - 6 = 15 \]
\[ -3x = 15 + 6 \]
\[ -3x = 21 \]
\[ x = \frac{21}{-3} \]
\[ x = -7 \]
Ответ: -7