Question

Simplify.

Answer 1

First off, nicely done on the exponents. You'd be surprised on how bad some look ,:D

a)
$(3xy^{3})(2x^{2}y)\\ (3*2)(x*x^{2})(y^{3}*y)\\\\ 6x^{3}y^{4}$

b)
$2y(2y+3y^{2})-y^{2}(3-y)\\ (4y^{2}+6y^{3}) + (-3y^{2}+y^{3})\\ (6y^{3}+y^{3})+(4y^{2}-3y^{2})\\ 7y^{3}+y^{2}\\\\ y^{2}(7y+1)$