1.25a^2-30a+9
2.4b^2-20b+25
3.9c^2-12c+4
4. 1+(mn)^3
5.(x-2y^2)-9y^2
6.2b^2+b-1
中三6題數唔識 !help
2008-01-19 7:53 pm
回答 (3)
2008-01-19 8:36 pm
✔ 最佳答案
1, (5a-3)^22, (2b-5)^2
3, (3c-2)^2
4, (mn+1)((mn)^2-mn+1)
5, x-11y^2 (呢條好似有d同其他題目有d格格不入)
6, (2b-1)(b+1)
2008-01-19 12:42:35 補充：
我諗第5題既問題應該係咁既:5, (x-2y)^2-9y^2 =x^2-4xy+4y^2-9y^2 =x^2-4xy-5y^2 =(x-5y)(x+y)如果題目係咁既話,咁就同其他5題就有d似樣!! 希望幫到你啦!! ^^
參考: me
2008-01-19 8:25 pm
1.25a^2-30a+9 = (5a-3)^2
2.4b^2-20b+25 = (2b-5)^2
3.9c^2-12c+4 = (3c-2)^2
4. 1+(mn)^3 = 1+mn^3
5.(x-2y^2)-9y^2 = x-11y^2
6.2b^2+b-1 = (2b-1)(b+1)
2.4b^2-20b+25 = (2b-5)^2
3.9c^2-12c+4 = (3c-2)^2
4. 1+(mn)^3 = 1+mn^3
5.(x-2y^2)-9y^2 = x-11y^2
6.2b^2+b-1 = (2b-1)(b+1)
收錄日期: 2021-04-13 14:59:47
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https://hk.answers.yahoo.com/question/index?qid=20080119000051KK01146