已知3x-y=1求代数式[(x^2+y^2)-(x-y)^2+2y(2x-y)]/4y的值_数学解答

已知3x-y=1求代数式[(x^2+y^2)-(x-y)^2+2y(2x-y)]/4y的值

人气：455 ℃　时间：2019-08-21 04:40:33

解答

原式=(x²+y²-x²+2xy-y²+4xy-2y²)/(4y)
=(6xy-2y²)/4y
=(3x-y)/2
=1/2(x²+y²-x²+2xy-y²+4xy-2y²)化简的对吗嗯