\[\boxed{\mathbf{1170\ (1162)}\mathbf{.}\mathbf{\ }Еуроки\ - \ ДЗ\ без\ мороки}\]
\[1)\ 20 - 4x =\]
\[= 8 \cdot (3x + 2,5) - 28x\]
\[20 - 4x = 24x + 20 - 28x\]
\[- 4x - 24x + 28x = 20 - 20\]
\[0 = 0\]
\[Ответ:\ x - любое\ число.\]
\[2)\ 4x + 9 = 5 \cdot (2x - 7) - 6x\]
\[4x + 9 = 10x - 35 - 6x\]
\[4x - 10x + 6x = - 35 - 9\]
\[4x - 10x + 6x = - 35 - 9\]
\[0 \neq - 44\]
\[Ответ:\ нет\ решения.\]