7. $6x + 3x - 9>25x - 15x + 50 - 10 - x$

Explanation:

Step1: Combine like terms on both sides

Left side: (6x + 3x-9=(6 + 3)x-9=9x-9) Right side: (25x-15x + 50-10-x=(25-15 - 1)x+(50 - 10)=9x + 40) The inequality becomes (9x-9>9x + 40)

Step2: Subtract (9x) from both sides

(9x-9-9x>9x + 40-9x) (-9>40)

Answer:

The inequality (-9>40) is false. So, the solution set of the inequality (6x + 3x-9>25x-15x + 50-10-x) is the empty set (\varnothing)