1a. Expand (x+y)²
1b. Using the result of (a), find the result (4a+5)²
初中數學問題
2007-10-23 12:32 am
回答 (3)
2007-10-23 12:37 am
✔ 最佳答案
1a.(x+y)2= x2+ 2xy+y2
By (a+b)2= a2+ 2ab+b2
1b.(4a+5)²
= (4a)2+ 2(4a)(5)+(5)2
=16a2+ 40a +25
2007-10-23 12:46 am
1a
(x+y)²
=(x+y) * (x+y)
=x*x+x*y+y*x+y*y
= x² +xy +xy +y²
=x²+2xy+y²
1b.
(4a+5)²
=(4a)² + 2(4a) * (5) + (5)²
=16a² + 30a+25
(x+y)²
=(x+y) * (x+y)
=x*x+x*y+y*x+y*y
= x² +xy +xy +y²
=x²+2xy+y²
1b.
(4a+5)²
=(4a)² + 2(4a) * (5) + (5)²
=16a² + 30a+25
參考: 自己
2007-10-23 12:43 am
1a.(x+y)2
= x^2+ 2xy+y^2
By (a+b)2= a^2+ 2ab+b^2
1b.(4a+5)²
= (4a)^2+ 2(4a)(5)+(5)^2
=16a^2+ 40a +25
= x^2+ 2xy+y^2
By (a+b)2= a^2+ 2ab+b^2
1b.(4a+5)²
= (4a)^2+ 2(4a)(5)+(5)^2
=16a^2+ 40a +25
參考: myself
收錄日期: 2021-04-29 19:44:22
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https://hk.answers.yahoo.com/question/index?qid=20071022000051KK01725