已知p=（x²）/（x-y）-（y²）/（x-y）Q=（x+y）²-2y（x+y）小敏小聪两人在x=2 y=-1的条件下分别计算P Q的值小敏说p值比Q大小聪说Q值比p大请你判断结论并说明理由

来源：学生作业学帮网编辑：学帮网时间：2024/05/27 01:01:10

P=(x²-y²)/(x-y)
=(x+y)(x-y)/(x-y)
=x+y
=2-1
=1
Q=(x+y)(x+y-2y)
=(x+y)(x-y)
=(2-1)×(2+1)
=3
所以P小聪说得对

P=(x²-y²)/(x-y)
=(x+y)(x-y)/(x-y)
=x+y
=2-1
=1
Q=(x+y)(x+y-2y)
=(x+y)(x-y)
=(2-1)×(2+1)
=3
所以P

已知p=（x²）/（x-y）-（y²）/（x-y）Q=（x+y）²-2y（x+y）小敏 小聪两人在x=2 y=-1的条件下分别计算P Q的值 小敏说p值比Q大 小聪说Q值比p大请你判断结论 并说明理由