Уравнение 1:
\( (x-70) \cdot 5 + 80 = 280 \)\( (x-70) \cdot 5 = 280 - 80 \)
\( (x-70) \cdot 5 = 200 \)
\( x-70 = 200 : 5 \)
\( x-70 = 40 \)
\( x = 40 + 70 \)
\( x = 110 \)
Уравнение 2:
\( 9600 : (x - 8 - 240) = 120 \)\( x - 8 - 240 = 9600 : 120 \)
\( x - 8 - 240 = 80 \)
\( x - 248 = 80 \)
\( x = 80 + 248 \)
\( x = 328 \)
Ответ: x = 110, x = 328.