Question

先化简,再求值:根号12xy^2-根号3x^5+b^2-y根号3xy^2+5x根号48x^2y,其中,x=3,y=2

Answer 1

=2y√(3x)-x^2√(3x)-y^2√(3x)+15xy√(3x)

=(2y-x^2-y^2+15xy)√(3x)

=(4-9-4+90)*3

=243