上海汉得股份有限公司:初一数学

来源:百度文库 编辑:中科新闻网 时间:2024/05/09 14:08:42
[(x+y)^3-(x^3+y^3)]/3(x-y)的值

[(x+y)^3-(x^3+y^3)]/3(x-y)
=[(x+y)(x^2+2xy+y^2)-(x+y)(x^2-xy+y^2)]/3(x-y)
=(x+y)(3xy)/3(x-y)
=xy(x+y)/(x-y)

(x+y)xy/(x-y)