Answer
$9x^4+12x^2y+4y^2$
Work Step by Step
FOIL the terms in the parentheses in order to distribute the multiplication. Then combine like terms to simplify.
$(3x^2+2y)^2$
$(3x^2+2y)(3x^2+2y)$
$9x^4+6x^2y+6x^2y+4y^2$
$9x^4+12x^2y+4y^2$