(x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)=

来源:学生作业帮助网 编辑:作业帮 时间:2024/11/14 14:32:39
(x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)=
x)ӨЭTFFqqM*5mmIQ_`gC;mQV Tn2XAnT"HRר9H3ye09Rk_\g4]^

(x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)=
(x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)=

(x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)=
(x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)
=(x-y) (x-2y)+(x-3y)[(x+2y) -2(x-4y)]
=(x-y)(x-2y)+(x-3y)[10y-x]
=x^2-xy-2xy+2y^2+10xy-3y^2-x^2+3xy
=-y^2+10xy
=y(10x-y)