乘法公式的几道题!化简:(-x-1)(x^2-x+1)的结果是( )a.-x^3+1 b.-x^3-1 c.x^3+1 d.x^3-1 (a^2-a+1)(a^2+a+1)(a^4-a^2+1)(x^2-y^2)(x+y)-2xy(x-y)(x+y)(a+b+c)^2-(b+c)^2-(c+2)^2-(a+b)^2(x^5-x^2)(x^10+x^7+x^4)

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乘法公式的几道题!化简:(-x-1)(x^2-x+1)的结果是( )a.-x^3+1 b.-x^3-1 c.x^3+1 d.x^3-1 (a^2-a+1)(a^2+a+1)(a^4-a^2+1)(x^2-y^2)(x+y)-2xy(x-y)(x+y)(a+b+c)^2-(b+c)^2-(c+2)^2-(a+b)^2(x^5-x^2)(x^10+x^7+x^4)
乘法公式的几道题!
化简:
(-x-1)(x^2-x+1)的结果是( )
a.-x^3+1 b.-x^3-1 c.x^3+1 d.x^3-1
(a^2-a+1)(a^2+a+1)(a^4-a^2+1)
(x^2-y^2)(x+y)-2xy(x-y)(x+y)
(a+b+c)^2-(b+c)^2-(c+2)^2-(a+b)^2
(x^5-x^2)(x^10+x^7+x^4)

乘法公式的几道题!化简:(-x-1)(x^2-x+1)的结果是( )a.-x^3+1 b.-x^3-1 c.x^3+1 d.x^3-1 (a^2-a+1)(a^2+a+1)(a^4-a^2+1)(x^2-y^2)(x+y)-2xy(x-y)(x+y)(a+b+c)^2-(b+c)^2-(c+2)^2-(a+b)^2(x^5-x^2)(x^10+x^7+x^4)
(1) B
(-x-1)(x^2-x+1)=-(x+1)(x^2-x+1)=-(x^3+1)=-x^3-1
(2)(a^2-a+1)(a^2+a+1)(a^4-a^2+1)
=(a^2+1-a)(a^2+1+a)(a^4-a^2+1)
=[(a^2+1)^2-a^2](a^4-a^2+1)
=(a^4+a^2+1)(a^4-a^2+1)
=(a^4+1)^2-(a^2)^2
=a^8+a^4+1
(3)(x^2-y^2)(x+y)-2xy(x-y)(x+y)
=(x+y)(x-y)(x+y-2xy)
(4)(a+b+c)^2-(b+c)^2-(c+a)^2-(a+b)^2
=a(a+2b+2c)-(c+a)^2-(a+b)^2
=a^2+2ab+2ac-c^2-2ac-a^2-a^2-2ab-b^2
=-c^2-a^2-b^2
(5)(x^5-x^2)(x^10+x^7+x^4)
=x^6(x^3-1)(x^6+x^3+1)
=x^6(x^9-1)
=x^15-x^6(3楼这错了吧)

(-x-1)(x^2-x+1)=-(x+1)(x^2-x+1)=-(x^3+1)=-x^3-1
b
(a^2-a+1)(a^2+a+1)(a^4-a^2+1)
=[(a^2+1)^2-a^2](a^4-a^2+1)
=(a^4+a^2+1) (a^4-a^2+1)
=(a^4+1) ^2-a^4
=a^8+a^4+1
(x^2-y^2)...

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(-x-1)(x^2-x+1)=-(x+1)(x^2-x+1)=-(x^3+1)=-x^3-1
b
(a^2-a+1)(a^2+a+1)(a^4-a^2+1)
=[(a^2+1)^2-a^2](a^4-a^2+1)
=(a^4+a^2+1) (a^4-a^2+1)
=(a^4+1) ^2-a^4
=a^8+a^4+1
(x^2-y^2)(x+y)-2xy(x-y)(x+y)
=(x-y)(x+y)(x+y-2xy)
=(x^2-y^2)(x+y-2xy)
(a+b+c)^2-(b+c)^2-(c+a)^2-(a+b)^2 (这里你打错了把是c+a不是c+2把)
=[(a+b+c)^2-(b+c)^2]-(c+a)^2-(a+b)^2
=a[a+2b+2c]-c^2-2ac-a^2-a^2-2bc-b^2
=-(a^2+b^2+c^2)
(x^5-x^2)(x^10+x^7+x^4)
=x^6*(x^3-1)(x^6+x^3+1)
=x^6*(x^9-1)
=x^15-x^9

收起

b
a^8+a^4+1
(x+y)*(x-y)^3 (应该是(x^2-y^2)(x+y-2xy),楼上对了)
-a^2-b^2-c^2
x^15+x^6