我想問下你地....
我有數學唔明...幫下我..唔該
好像(4x-5y)2次方-(5x-4y)2次方 禁樣..
我要有步驟同答案..thx...最好15題以上
緊急(10分)(10分)(10分)緊急(10分)(10分)(10分)
2006-12-15 3:21 am
回答 (4)
2006-12-15 4:01 am
(4x-5y)2次方-(5x-4y)2次方
=(16x-25y)-(25x-16y)
=16x-25y-25x+16y
=-9x-9y
=(16x-25y)-(25x-16y)
=16x-25y-25x+16y
=-9x-9y
2006-12-15 3:32 am
(4x-5y)2次方-(5x-4y)2次方
=16x2次方-40xy+25y2次方-25x2次方-40xy+16y2次方
=36y2次方-9x2次方-80xy
=16x2次方-40xy+25y2次方-25x2次方-40xy+16y2次方
=36y2次方-9x2次方-80xy
2006-12-15 3:32 am
(4x-5y) 2-(5x-4y) 2
=(4x-5y)(4x-5y)-(5x-4y)(5x-4y)
=16x 2-20xy-20xy+25y 2
=16x 2-40xy+25y 2
=(4x-5y)(4x-5y)-(5x-4y)(5x-4y)
=16x 2-20xy-20xy+25y 2
=16x 2-40xy+25y 2
2006-12-15 3:28 am
(4x-5y)2次方-(5x-4y)2次方
=(16x-25y)-(25x-16y)
=(16x-25x)-(25y-16y)
= -9x-9y
2006-12-14 20:03:52 補充：
(4x-5y)2次方-(5x-4y)2次方=(16x^2-25y^2)-(25x^2-16y^2)=(16-25)x2次方-(25-16)y2次方= -9x^2-9y^2= -(3x)2次方-(3y)2次方~~~~~~~~~~~~~~~~~~~~補充^2=2次方~~~~~
=(16x-25y)-(25x-16y)
=(16x-25x)-(25y-16y)
= -9x-9y
2006-12-14 20:03:52 補充：
(4x-5y)2次方-(5x-4y)2次方=(16x^2-25y^2)-(25x^2-16y^2)=(16-25)x2次方-(25-16)y2次方= -9x^2-9y^2= -(3x)2次方-(3y)2次方~~~~~~~~~~~~~~~~~~~~補充^2=2次方~~~~~
收錄日期: 2021-04-12 18:19:08
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20061214000051KK03247