(1)(x+y)^2-4(x+y)-12 (2)12(x+y)^2+11(x+y)(x-y)+2(x-y)^2 (3)5+7(a+1)-6(a+1)^2 (4)(a-2b)^2-8(a-2b)+12(5)x^6-19x^3y^3-216y^6(6)(x^2+x+4)^2+8x(x^2+x+4)+15x^2 (7)(x^2+x)^2-14(x^2+x)+24题目比较多,必将重谢
问题描述：
(1)(x+y)^2-4(x+y)-12
(2)12(x+y)^2+11(x+y)(x-y)+2(x-y)^2
(3)5+7(a+1)-6(a+1)^2
(4)(a-2b)^2-8(a-2b)+12
(5)x^6-19x^3y^3-216y^6
(6)(x^2+x+4)^2+8x(x^2+x+4)+15x^2
(7)(x^2+x)^2-14(x^2+x)+24
题目比较多,必将重谢
答
(1)(x+y)^2-4(x+y)-12=(x+y-6)(x+y+2)(2)12(x+y)^2+11(x+y)(x-y)+2(x-y)^2=[3(x+y)+2(x-y)]*[4(x+y)+x-y]=(5x+y)(5x+3y)(3)5+7(a+1)-6(a+1)^2=[5-3(a+1)]*[1+2(a+1)]=(2-3a)(3+2a)(4)(a-2b)^2-8(a-2b)+12=(a-2b-2)(a...