Question

求数学学霸帮忙解答！！！！

Answer 1

(1)=X^3(x+2)-(7x^2+8x-12)=x^3(x+2)-(7x-6)(x+2)=(x+2)(x^3-7x+6)=(x+2)(x^3-x^2+x^2-7x+6)=(x+2)[(x^3-x^2)+(x^2-7x+6)]=)=(x+2)[(x^2(x-1)+(x-6)(x-1)]=(x+2)(x-1)(x^2+x-6)=(x+2)(x-1)(x-2)(x+3)
(2)=a^n(a^2+ab-6b^2)=a^n(a+3b)(a-2b)
(3)=y^2[(x^2-2x)^3+1]=y^2[(x^2-2x)+1][(x^2-2x)^2+(x^2-2x)+1]=y^2(x-1)^2(x^4-4x^3+5x^2-2x+1)
(4)=(x+a)^2-(y-b)^2=(x+a+y-b)(x+a-y+b)
(5)=
2.a^2+b^2+c^2-ab-bc-ca=0 (2a^2+2b^2+2c^2-2ab-2bc-2ca)/2=0 (a^2-2ab+b^2+b^2-2bc+c^2+c^2-2ca+a^2)/2=0 [(a-b)^2+(b-c)^2+(c-a)^2]/2=0 a-b=0 b-c=0 c-a=0 a=b=c 等边三角形
3.
,因有事,等有时间再补充(5)和3