化简求值:[(x+y)^2-y(2x+y)-8x]÷2x;其中x=2,y=2012.

问题描述:

化简求值:[(x+y)^2-y(2x+y)-8x]÷2x;其中x=2,y=2012.

原式=(x^2+2xy+y^2-2xy-y^2-8x)÷2x=(x^2-8x)÷2x=(x-8)÷2=-3

[(x+y)^2-y(2x+y)-8x]÷2x
=(x²+2xy+y²-2xy-y²-8x)÷2x
=(x²-8x)÷2x
=x/2-4
=2/2-4
=1-4
=-3

原式=(x^2+2xy+y^2-2xy-y^2-8x)÷2x=(x-8)÷2=-3