1.a^2-9b^2+a-3b 2.m^4-4m^3+4m^2-9 3.4x^2-5x-6 4.(x+y)+2(x+y)-15 5.2a^2-4ab+2b^2-a+b-3 2.(x^2+x)(x^2+x-5)+6 补充:a^2表示a的2次方,依此类推,

问题描述:

1.a^2-9b^2+a-3b 2.m^4-4m^3+4m^2-9 3.4x^2-5x-6 4.(x+y)+2(x+y)-15 5.2a^2-4ab+2b^2-a+b-3 2.(x^2+x)(x^2+x-5)+6 补充:a^2表示a的2次方,依此类推,

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1,
(a-3b)(a+3b)+a=3b
=(a-3b)(a+3b+1)
2)
m^4-4m^3+4m^2-9
=(m^2-2m)^2-9
=(m^2-2m-3)(m^2-2m+3)
=(m-3)(m+1)(m^2-2m+3)
3)
4x^2-5x-6=(4x+3)(x-2)
4)
(x+y)^2+2(x+y)-15吧
=(x+y+5)(x+y-3)
5)
2a^2-4ab+2b^2-a+b-3
=2(a-b)^2-(a-b)-3
=(2a-2b-3)(a-b+1)
6)
(x^2+x)(x^2+x-5)
=(x^2+x)^2-5(x^2+x)+6
=(x^2+x-2)(x^2+x-3)
=(x+2)(x-1)(x^2+x-3)

1.原式=(a+3b)(a-3b)+(a-3b)=(a-3b)(a+3b+1)2.原式=m^2(m^2-4m+4)-9=m^2(m-2)^2-9=[m(m-2)+3][m(m-2)-3]=(m^2-2m+3)(m^2-2m-3)=(m+1)(m-3)(m^2-2m+3)3.原式=(x-2)(4x+3)(十字相乘法)4.原式=3(x+y)-15=3(x+y-5)5.原...