$3\square 5=2\square x \implies 15+3+5=2x+2+x$, hence $x=7$. 
Let $$a\square b=ab+a+b$$ for any integers $$a$$ and $$b$$.  The solution of the equation $$3\square 5=2\square x$$ is: $x = $~\uline{~~~~~~~~~~}~ 
Options:
[A] $$3$$ 
[B] $$6$$ 
[C] $$7$$ 
[D] $$10$$ 
[E] $$12$$ 