因式分解: m(x+y)^2 - 4m(x-y)^2

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Andy

2007-09-23 7:51 am

I don't know hot to do, please help me.

更新1:

I have the answer, but i don't know how to do it!!!!!

更新2:

The answer is: - m ( 3x - y )( x - 3y )

回答 (4)

Gabriella Montez

2007-09-23 7:58 am

✔ 最佳答案

m(x+y)^2 - 4m(x-y)^2

= m [ ( x + y )^2 - 4 ( x - y )^2 ] [ Take out m as common factor ]

= m [ ( x + y ) + 2 ( x - y ) ] [ ( x + y ) - 2 ( x - y ) ] [By a^2-b^2 = ( a + b )( a - b ) ]

= m ( x + y + 2x - 2y )( x + y - 2x + 2y )

= m ( 3x - y )( - x + 3y )

= - m ( 3x - y )( x - 3y )

參考: My Maths Knowledge

👍 1 👎 0

[匿名]

2007-09-23 8:11 am

m(x+y)^2-4m(x-y)^2
=m[(x+y)^2-4(x-y)^2]
=m{(x+y)^2-[2(x-y)]^2}
=m{[x+y+2(x-y)] [x+y-2(x-y)]}
=m(3x-y)(y-x)

i hope it is correct....

參考: By myself

👍 0 👎 0

Michelle

2007-09-23 8:01 am

exp = m(x^2+2xy+y^2)-4m(x^2-2xy+y^2)
= mx^2+2mxy+my^2-4mx^2+8mxy-4my^2
=-3mx^2+10mxy-3my^2
=-(3mx^2+10mxy+3my^2)
=-m(3x^2+10xy+3y^2)
=-m(3x+1)(x+3)

ANS = -m(3x+1)(x+3)

參考: myself

👍 0 👎 0

[匿名]

2007-09-23 7:57 am

=-3m(x+y)^2

參考: 自己計

👍 0 👎 0

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