一些分解因式的数学题~HELP!(1)m(x-y)²-x+y(2)(a-b)²-3a+3b(3)已知a+b=2,ab=-½,求a(a+b)(a-b)-a(a+b)²的值.

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一些分解因式的数学题~HELP!(1)m(x-y)²-x+y(2)(a-b)²-3a+3b(3)已知a+b=2,ab=-½,求a(a+b)(a-b)-a(a+b)²的值.
一些分解因式的数学题~HELP!
(1)m(x-y)²-x+y
(2)(a-b)²-3a+3b
(3)已知a+b=2,ab=-½,求a(a+b)(a-b)-a(a+b)²的值.

一些分解因式的数学题~HELP!(1)m(x-y)²-x+y(2)(a-b)²-3a+3b(3)已知a+b=2,ab=-½,求a(a+b)(a-b)-a(a+b)²的值.
(1)m(x-y)²-x+y
=m(y-x)(y-x)+(y-x)
=(y-x)(my-mx+1)
(2)(a-b)²-3a+3b
=(b-a)²+3(b-a)
=(b-a)(b-a+3)
(3)a(a+b)(a-b)-a(a+b)²
=a(a+b)(a-b)-a(a+b)(a+b)
=a(a+b)(a-b-a-b)
=a(-2b)(a+b)
=-2ab(a+b)
∵a+b=2,ab=-½
∴原式=-2*(-½)*2
=2
这些因式分解都是以合并同类项为基础变形的式子
用心做就可以做出来
姐姐都上初二了,应该错不了吧

(1)m(x-y)²-x+y
=m(x-y)^2-(x-y)
=[m(x-y)-1](x-y)
(2)(a-b)²-3a+3b
=(a-b)^2-3(a-b)
=(a-b-3)(a-b)
(3)已知a+b=2,ab=-1/2,
求a(a+b)(a-b)-a(a+b)²的值。
=[a(a-b)-a(a+b)](a+b)
=[a(a-b-a-b)](a+b)
=[a(-2b)](a+b)
=-2ab(a+b)
=2