Is this simplified?

6a2 + 4a2b - 4ab - 3b

*The 2's are exponents

yes

Ok thanks!

You could also write it as

6a^2 + b(4a^2 -4a -3)
= 6a^2 + b(2a +1)(2a -3)

That has even more terms, but looks better to me.

Yes, the expression 6a^2 + 4a^2b - 4ab - 3b is simplified.