＊請列出步驟
5(3m-n)2 -(n-3m)
注意*(3m-n)2 =( 3m-n ) 的二次方
F.2的問題
2007-10-17 3:32 am
回答 (3)
2007-10-17 3:43 am
✔ 最佳答案
5(3m-n)^2 -(n-3m)= 5(3m - n)^2 + (3m - n)
= (3m - n)[5(3m - n) + 1]
2007-10-17 4:41 am
方法<1>
5(3m-n)2 -(n-3m)
= 5[(3m-n)(3m-n)]-(n-3m)
=5(9m2-3mn-3mn+n2)-(n-3m)
=5(9m2-6mn+ n2)-(n-3m)
=45 m2-30mn+5n2-n+3m
方法<2>
5(3m-n)2 -(n-3m)
=5[(3m)2+2(3m)(-n)+(-n)2]-(n-3m)
=5[9m2+6m(-n)+n2]-n+3m
=5(9m2-6mn+n2)-n+3m
=45 m2-30mn+5n2-n+3m
5(3m-n)2 -(n-3m)
= 5[(3m-n)(3m-n)]-(n-3m)
=5(9m2-3mn-3mn+n2)-(n-3m)
=5(9m2-6mn+ n2)-(n-3m)
=45 m2-30mn+5n2-n+3m
方法<2>
5(3m-n)2 -(n-3m)
=5[(3m)2+2(3m)(-n)+(-n)2]-(n-3m)
=5[9m2+6m(-n)+n2]-n+3m
=5(9m2-6mn+n2)-n+3m
=45 m2-30mn+5n2-n+3m
收錄日期: 2021-04-13 13:56:47
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https://hk.answers.yahoo.com/question/index?qid=20071016000051KK02887