Question 33182
(3X^2+5X+1)-(2x-3)
= (3x^2+5x-2x+1+3)
= 3x^2+3x+4
It cannot be factored further.  You need an equation to solve.  The question appears as an expression, which can be simplified only.
.....
The solution set for 3-x>7 is derived as below:
3-x > 7
Subtract 3 from both sides of the above inequality:
=> 3-x-3 > 7-3
=> -x > 4
Multiply both sides with (-1):
=> x > -4
The solution set is x belongs to (-4, infinity)