分组分解法的题,分解因式,请高手写出步骤,谢谢!
1.x^2-2xy+y^2-5x+5y-6
2.ab(c^2-d^2)-cd_a^2-b^2)
3x^2-4xy+4y^2-x+2y-6
4.a^2+2ab+b^2-c^2
分组分解法的题,分解因式,请高手写出步骤,谢谢!
1.x^2-2xy+y^2-5x+5y-6
2.ab(c^2-d^2)-cd_a^2-b^2)
3x^2-4xy+4y^2-x+2y-6
4.a^2+2ab+b^2-c^2
1.X²—2XY+Y²—5X+5Y—6
=(X—Y)²—5(X—Y+1)—1
=(X—Y+1)(X—Y—1)—5(X—Y+1)
=(X—Y+1)(X—Y—1—5)
=(X—Y+1)(X—Y—6)
1、x^2-2xy+y^2-5x+5y-6=(x-y)^2-5(x-y)-6=(x-y-6)(x-y+1)
2、ab(c^2-d^2)-cd_a^2-b^2)=这题错了吧?
3、3x^2-4xy+4y^2-x+2y-6=(x-2y)^2-(x-2y)-6=(x-2y-3)(x-2y+2)
4、a^2+2ab+b^2-c^2=(a+b)^2-c^2=(a+b+c)(a+b-c)
1.x^2-2xy+y^2-5x+5y-6=x^2-2xy+y^2-1-5x+5y-5=(x-y)^2-1^2-5(x-y+1)=(x-y+1)(x-y-1)-5(x-y+1)=(x-y+1)(x-y-6)
2,abc^2-abd^2-cda^2+cdb^2,把第1项和第3项目结合,把第2和第4结合得(ac+bd)(bc-ad)
3,(x^2-4xy+4y^2)-x+2y-4-2=(x-2y)^2-4-(x-2y+2)=(x-2y+2)(x-2y-2)-(x-2y+2)=(x-2y+2)(x-2y-3)
4.(a+b)^2-c^2=(a+b+c)(a+b-c)
.a^2+2ab+b^2-c^2=(a+b)^2-c^2
=(a+b-c)(a+b+c)