若x-y=1,则x方-y方-2y-5=

来源:学生作业帮助网 编辑:六六作业网 时间:2024/12/27 14:09:09
若x-y=1,则x方-y方-2y-5=若x-y=1,则x方-y方-2y-5=若x-y=1,则x方-y方-2y-5=x方-y方-2y-5=(x+y)(x-y)-2y-5=(x+y)×1-2y-5=x+y

若x-y=1,则x方-y方-2y-5=
若x-y=1,则x方-y方-2y-5=

若x-y=1,则x方-y方-2y-5=
x方-y方-2y-5
=(x+y)(x-y)-2y-5
=(x+y)×1-2y-5
=x+y-2y-5
=x-y-5
=1-5
=-4

x^2-y^2-2y-5
=(x+y)(x-y)-2y-5
=x+y-2y-5
=x-y-5
=1-5
=-4

(x+y)(x--y)-2y-5
=x+y-2y-5
=x-y-5
=-4