Question

初中因式分解

（1）x^2-y^2-2x-4x-3
(2)x^2-4y^2-9z^2-12yz
(3)ma^2-4ma+4m 要过程

Answer 1

我写了详细过程，希望能帮助你！

Answer 2

1,应该是x^2-y^2-2x-4y-3=(x-1)^2-(y+2)^2=(x-1+y+2)(x-1-y-2)=(x+y+1)(x-y-3)
2.x^2-4y^2-9z^2-12yz=x^2-(2y+3z)^2=(x-2y-3z)(x+2y+3z)

3.ma^2-4ma+4m=m(a-2)^2

Answer 3

其实你只要想一下完全平方公式和平方差公式就可以了，切记初中数学没有难题目，只要把知识点搞懂，然后在做题的时候灵活一点就可以了

(1)x^2-y^2-2x-4y-3
=(x^2-2x 1)-(y^2 4y 4)
=(x-1)^2-(y 2)^2
=(x-1 y 2)(x-1-y-2)
=(x y 1)(x-y-3)
(2)x^2-4y^2-9z^2-12yz
=x^2-(4y^2 9z^2 12yz)
=x^2-(2y 3z)^2
=(x 2y 3z)(x-2y-3z)
(3)ma^2-4ma 4m
=m(a^2-4a 4)
=m(a-2)^2

Answer 4

(1)x^2-y^2-2x-4y-3
=(x^2-2x 1)-(y^2 4y 4)
=(x-1)^2-(y 2)^2
=(x-1 y 2)(x-1-y-2)
=(x y 1)(x-y-3)
(2)x^2-4y^2-9z^2-12yz
=x^2-(4y^2 9z^2 12yz)
=x^2-(2y 3z)^2
=(x 2y 3z)(x-2y-3z)
(3)ma^2-4ma 4m
=m(a^2-4a 4)
=m(a-2)^2
这三道因式分解题主要应用了完全平方公式a^2 2ab b^2=(a b)^2
a^2-2ab b^2=(a-b)^2和平方差公式a^2-b^2=(a b)(a-b)

Answer 5

(1）x^2-y^2-2x-4x-3
=x^2-2x+1-y^2-4x-4
=(x-1)^2-(y^2+4x+4)
=(x-1)^2-(y+2)^2
=(x-1+y+2)(x-1-y-2)
=(x+y+1)(x-y-3)

(2)x^2-4y^2-9z^2-12yz
=x^2-(2y)^2-(3z)^2-2*2y*3z
=x^2-(2y+3z)^2
=(x+2y+3z)(x-2y-3z)

(3)ma^2-4ma+4m
=m(a^2-4a+4)
=m(a-2)^2