Решение:
\[ 3(x + 10) - 2(x - 10) = 10 \]
\[ 3x + 30 - 2x + 20 = 10 \]
\[ (3x - 2x) + (30 + 20) = 10 \]
\[ x + 50 = 10 \]
\[ x = 10 - 50 \]
\[ x = -40 \]
Ответ: -40