用公因式发解下列多项式(1)6a(b-a)^2-2(a-b)^3(2)m(x-y)-x+y(3)(x-3)^2+(3x-9)(4)a(a-b-c)+b(b+c-a)+c(c-a+b)(5)(2x-3y)(a+b)+(3x-2y)(a+b)(6)2a+4b-3ma-6mb用简便方法计算(7)2005+2005^2-2006^2
问题描述:
用公因式发解下列多项式
(1)6a(b-a)^2-2(a-b)^3
(2)m(x-y)-x+y
(3)(x-3)^2+(3x-9)
(4)a(a-b-c)+b(b+c-a)+c(c-a+b)
(5)(2x-3y)(a+b)+(3x-2y)(a+b)
(6)2a+4b-3ma-6mb
用简便方法计算
(7)2005+2005^2-2006^2
答
用公因式发解下列多项式
(1)6a(b-a)^2-2(a-b)^3
=6a(a-b)²-2(a-b)³
=2(a-b)²(3a-a+b)
=2(a-b)²(2a+b)
(2)m(x-y)-x+y
=m(x-y)-(x-y)
=(x-y)(m-1)
(3)(x-3)^2+(3x-9)
=(x-3)²+3(x-3)
=(x-3)(x-3+3)
=x(x-3)
(4)a(a-b-c)+b(b+c-a)+c(c-a+b)
=a(a-b-c)-b(a-b-c)-c(a-b-c)
=(a-b-c)²
(5)(2x-3y)(a+b)+(3x-2y)(a+b)
=(a+b)(2x-3y+3x-2y)
=(a+b)(5x-5y)
=5(a+b)(x-y)
(6)2a+4b-3ma-6mb
=2(a+2b)-3m(a+2b)
=(a+2b)(2-3m)
(7)2005+2005^2-2006^2
=2005(1+2005)-2006²
=2005×2006-2006²
=2006(2005-2006)
=-2006