已知x+y=6,xy=-2,求（x的4次方-y的4次方）除以x²+y²/xy除以（6x-6y)的值_数学解答

已知x+y=6,xy=-2,求（x的4次方-y的4次方）除以x²+y²/xy除以（6x-6y)的值

人气：286 ℃　时间：2020-03-15 22:44:28

解答

原式=(x²+y²)(x²-y²)*xy/(x²+y²)÷(6x-6y)
=xy(x+y)(x-y)÷6(x-y)
=xy(x+y)/6
=-2×6/6
=-2