作业帮(1)(x+1)^2(x-1)+2(x+1)(x-1)^2(2)-1/9a^2+25(3)-4x^2-12x-9(6)2x^3-8x(7)81-x^4(8)(x-1)^2-4y^2(9)2-8(x+2)^2
来源：学生作业帮助网 编辑：作业帮 时间：2024/05/11 18:34:27
(1)(x+1)^2(x-1)+2(x+1)(x-1)^2(2)-1/9a^2+25(3)-4x^2-12x-9(6)2x^3-8x(7)81-x^4(8)(x-1)^2-4y^2(9)2-8(x+2)^2
(1)(x+1)^2(x-1)+2(x+1)(x-1)^2(2)-1/9a^2+25(3)-4x^2-12x-9(6)2x^3-8x(7)81-x^4
(8)(x-1)^2-4y^2(9)2-8(x+2)^2
(1)(x+1)^2(x-1)+2(x+1)(x-1)^2(2)-1/9a^2+25(3)-4x^2-12x-9(6)2x^3-8x(7)81-x^4(8)(x-1)^2-4y^2(9)2-8(x+2)^2
(x+1)^2(x-1)+2(x+1)(x-1)^2
=(x+1)(x-1)[(x+1)+2(x-1)^2]
=(x+1)(x-1)(x+1+2x-2)
=(x+1)(x-1)(3x-1)
-1/9a^2+25
=25-1/9a^2
=(5+1/3a)(5-1/3a)
-4x^2-12x-9
=-(4x^2+12x+9)
=-(2x+3)^2
2x^3-8x
=2x(x^2-4)
=2x(x+2)(x-2)
81-x^4
=(9-x^2)(9+x^2)
=(3-x)(3+x)(9+x^2)
(x-1)^2-4y^2
=(x-1+2y)(x-1-2y)
2-8(x+2)^2
=2[1-4(x+2)^2]
=2[1-2(x+2)][1+2(x+2)]
=2(1-2x-4)(1+2x+4)
=2(-2x-3)(2x+5)
=-2(2x+3)(2x+5)
因式分解吗？以后不要这样发题，别人看不清，谁帮你做呢。
(1)(x+1)^2(x-1)+2(x+1)(x-1)^2=(x+1)(x-1)(x+1+2x-2)=(x+1)(x-1)(3x-1)
(2)-1/9a^2+25=5^2-(1/3a)^2=(5+1/3a)(5-1/3a)
(3)-4x^2-12x-9=-(4x^2+12x+9)=-(2x+3)^2
(6)2x...
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因式分解吗？以后不要这样发题，别人看不清，谁帮你做呢。
(1)(x+1)^2(x-1)+2(x+1)(x-1)^2=(x+1)(x-1)(x+1+2x-2)=(x+1)(x-1)(3x-1)
(2)-1/9a^2+25=5^2-(1/3a)^2=(5+1/3a)(5-1/3a)
(3)-4x^2-12x-9=-(4x^2+12x+9)=-(2x+3)^2
(6)2x^3-8x=2x(x^2-4)=2x(x+2)(x-2)
(7)81-x^4=(9+x^2)(9-x^2)=(9+x^2)(3+x)(3-x)
(8)(x-1)^2-4y^2=(x-1+2y)(x-1-2y)=(x+2y-1)(x-2y-1)
(9)2-8(x+2)^2=2[1-4(x+2)^2]=2(1+2x+4)(1-2x-4)=-2(2x+5)(2x+3)
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