全要过程(a+1)(a-1)(a的2方-1)=过程
2个回答

(a+1)(a-1)(a^2-1)=(a^2-1)^2=a^4-2a^2+1

(x-2)(x+2)(x^2+4)=(x^2-4)(x^2+4)=x^2-16

(x+3y)^2+2(x-y)(x+y)+(x-3y)^2

=x^2+6xy+9y^2+2x^2-2y^2+x^2-6xy+9y^2

=4x^2-16y^2

[(a-1/2)^2+(a+1/2)^2](2a^2-1/2)

=(a^2-a+1/4+a^2+a+1/4)(2a^2-1/2)

=(2a^2+1/2)(2a^2-1/2)

=4a^4-1/4

(a+2b-3)(a+2b+3)

=[(a+2b)-3][(a+2b)+3]

=(a+2b)^2-3^2

=a^2+4ab+4b^2-9

(x^2+x+3)(x^2-x-3)

=[x^2+(x+3)][x^2-(x+3)]

=x^4-(x+3)^2

=x^4-x^2-6x-9

(x+2y+3)^2-(x-2y+3)(x-2y-3)

=[(x+2y)+3]^2-[(x-2y)+3][(x-2y)-3]

=(x+2y)^2+6(x+2y)+9-(x-2y)^2+9

=[(x+2y)^2-(x-2y)^2]+6(x+2y)+18

=(x+2y+x-2y)(x+2y-x+2y)+6x+12y+18

=2x*4y+6x+12y+18

=8xy+6x+12y+18