(X-2y)^2-9a^2-54ay-81y^2
如何因式分解?
請詳解...plx
另一個一元二次既問題:(中學)
2006-10-18 8:02 am
回答 (3)
2006-10-18 7:02 pm
✔ 最佳答案
(x-2y)^2-9a^2-54ay-81y^2=(x-2y)^2+(-9a^2-54ay-81y^2)
=(x+2y)^2+(-1)(9a^2-54ay-81y^2)
=(x+2y)^2-(9a^2+54ay+81y^2)
=(x+2y)^2-[(3a)^2+2(3a)(9y)+(9y)^2]
=(x-2y)^2-(3a+9y)^2.....................................(a+b)^2=a^2+2ab+b^2
=[(x-2y)+(3a+9y)][(x-2y)-(3a+9y)...................a^2-b^2=(a+b)(a-b)
=(x-2y+3a+9y)(x-2y-3a-9y)
=(x+7y+3a)(x-11y-3a)
2006-10-18 8:12 am
(x-2y)^2 - 9a^2 - 54ay - 81y^2
= (x-2y)^2 - (9a^2 + 54 ay + 81y^2)
= (x-2y)^2 - (3a + 9y)^2
= [(x-2y) + (3a + 9y)] [(x - 2y) - (3a + 9y)]
= [x-2y+3a+9y] [x-2y-3a-9y]
= (x+7y+3a) (x-11y-3a)
= (x-2y)^2 - (9a^2 + 54 ay + 81y^2)
= (x-2y)^2 - (3a + 9y)^2
= [(x-2y) + (3a + 9y)] [(x - 2y) - (3a + 9y)]
= [x-2y+3a+9y] [x-2y-3a-9y]
= (x+7y+3a) (x-11y-3a)
參考: myself
2006-10-18 8:08 am
(X-2y)2-9a2-54ay-81y2
= (X-2y)2 -(9a2+54ay+81y2)
= (X-2y)2 - (3a+9y)2
= [(X-2y)+(3a+9y)][(X-2y)-(3a+9y)]
= (X-2y+3a+9y)(X-2y-3a-9y)
= (X+7y+3a)(X-11y-3a)
= (X-2y)2 -(9a2+54ay+81y2)
= (X-2y)2 - (3a+9y)2
= [(X-2y)+(3a+9y)][(X-2y)-(3a+9y)]
= (X-2y+3a+9y)(X-2y-3a-9y)
= (X+7y+3a)(X-11y-3a)
收錄日期: 2021-04-12 19:04:50
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