圆式=[(-4/3)*(根号12)x^2*(根号3)x/y]/[(2/5)*(根号4)*y/x]
=[(-4/3)*2根号3×x^2*(根号3)*x/y]*5x/4y
=(-8/3)*3x^2*5/4
=-10x^2
=-10 (x=1)