\[\boxed{\text{392\ (392).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[2x \cdot 6 - 5 \cdot (x + 18) =\]
\[= 23 \cdot 30 + x\]
\[12x - 5x - 90 = 690 + x\]
\[7x - x = 690 + 90\]
\[6x = 780\]
\[x = 130.\]
\[20 \cdot (x - 1) + 12 \cdot (2x + 1) =\]
\[= 15 \cdot (3x - 1)\]
\[20x - 20 + 24x + 12 = 45x - 15\]
\[44x - 45x = - 15 + 8\]
\[- x = - 7\]
\[\ x = 7.\]