If so:

Since the algebraic expression has nothing to do with the value of x, it means that the item with x in the algebraic expression can be cancelled; You can get:

2x？ -2bx？ =0 and ax+3x=0, a =-3, b =1;

So 3a? -2b？ -(2a？ -ab+3b？ )

=a？ -5b？ +ab

=9-5-3

= 1