1.已知y=2x,求(2x+y/x^2-2xy+y^2)乘以(x-y)的值.2.计算题：a-2b+(4b^2/a+2b)+(4a^2b/a^2-4b^2)

(2x+y)/(x^2-2xy+y^2)*(x-y)=(2x+y)/(x-y)^2*(x-y)=(2x+2x)(x-2x)/(x-2x)^2=4x(-x)/(-x)^2=-4x^2/x^2=-4a-2b+4b^2/(a+2b)+4a^2b/(a^2-4b^2)=[(a-2b)(a+2b)+4b^2]/(a+2b)+4a^2b/[(a-2b)(a+2b)]=(a^2-4b^2+4b^2)/(a+2b...