{(x+y)²-(x-y)²}÷(-4xy)= (3xy-y)÷y=还有(x+y)²÷(x+y)

来源:学生作业学帮网 编辑:学帮网 时间:2024/05/27 00:20:21

{(x+y)²-(x-y)²}÷(-4xy)= (3xy-y)÷y=
还有(x+y)²÷(x+y)

{(x+y)²-(x-y)²}÷(-4xy)=[x^2+2xy+y^2-(x^2-2xy+y^2]/(-4xy)=4xy/(-4xy)=-1
(3xy-y)÷y=3xy/y-y/y=3x-1