Answer
(a.) $3x^2$.
(b.) $ 6x^2y^2$.
Work Step by Step
(a.) The given expression is
$3x^3\cdot ?=9x^5$
Divide both sides by $3x^3$
$\frac{1}{3x^3}\cdot 3x^3\cdot ?=\frac{1}{3x^3}\cdot9x^5$
Simplify.
$ ?=3x^2$
(b.) The given expression is
$2x^3y^2\cdot ? =12x^5y^4$
Divide both sides by $2x^3y^2$.
$\frac{1}{2x^3y^2} \cdot 2x^3y^2\cdot ? =\frac{1}{2x^3y^2} \cdot12x^5y^4$
Simplify.
$ ? =6x^2y^2$.
