Multiply (a - 3)(a^2 + 3a + 9)(a^2 - 2b).?
回答 (7)
2009-01-30 4:42 pm
✔ 最佳答案
(a - 3)(a^2 + 3a + 9)(a^2 - 2b)=a^3+3a^2+9a-3a^2-9a-27)(a^2-2b)
=(a^3-27)(a^2-2b)
=a^5-2a^3b-27a^2+54b answer//
2009-01-30 5:33 pm
(a - 3)(a^2 + 3a + 9)(a^2 - 2b)
= (a^3 - 3a^2 + 3a^2 - 9a + 9a - 27)(a^2 - 2b)
= (a^3 - 27)(a^2 - 2b)
= a^5 - 27a^2 - 2a^3b + 54b
= (a^3 - 3a^2 + 3a^2 - 9a + 9a - 27)(a^2 - 2b)
= (a^3 - 27)(a^2 - 2b)
= a^5 - 27a^2 - 2a^3b + 54b
2009-01-30 4:36 pm
well all of your a^ have to go togather and your 3 and 9 have to go togather sense there is no letter in front then your 2b has to work by its self but sense it is in ( ) you have to muliply and then you can add the letters togathr 9-3 =6 then your 6 answer and your 3a go togather adding of course 3 and 6 get you back to 9 then take your a^2 times it by the a^2= a^4 then you take the 2b sense there is a mines in that it is a negative 2b so 9 times 4a times 2 b sense you can times different letters you would get 9times 8ab as your answer
2009-01-30 4:32 pm
ok let's see
(a-3)(a^2 + 3a + 9)(a^2 - 2b)
not sure exactly...but the first step is to find the common denominator and divide the equation by that..so for instance
(a-3)(a^2 + 3a + 9)(a^2 - 2b)
--------------------------------------
(common denominator)
after that then everything should be pretty easy.
I forgot how to find the common denominator, otherwise i would have solved it.
(a-3)(a^2 + 3a + 9)(a^2 - 2b)
not sure exactly...but the first step is to find the common denominator and divide the equation by that..so for instance
(a-3)(a^2 + 3a + 9)(a^2 - 2b)
--------------------------------------
(common denominator)
after that then everything should be pretty easy.
I forgot how to find the common denominator, otherwise i would have solved it.
2009-01-30 4:29 pm
I presume you want the brackets expanding?
well i'd do it in 2 steps:
(a-3)(a^2 - 2b) =
then multiply that by the middle bracket:
(a^3 -2ab -3a^2 +6b)(a^2 + 3a +9) =a^5 +3a^4 + 9a^3 - 2a^3b - 6a^2b - 18ab - 3a^4 -9a^3 -27a^2 +6a^2b +18ab +54b
Then simplifying
a^5 - 2a^3b -27a^2 +54b
well i'd do it in 2 steps:
(a-3)(a^2 - 2b) =
then multiply that by the middle bracket:
(a^3 -2ab -3a^2 +6b)(a^2 + 3a +9) =a^5 +3a^4 + 9a^3 - 2a^3b - 6a^2b - 18ab - 3a^4 -9a^3 -27a^2 +6a^2b +18ab +54b
Then simplifying
a^5 - 2a^3b -27a^2 +54b
2009-01-30 4:28 pm
(a - 3)(a^2 + 3a + 9) = a^3 + 3a + 9a - 3a^2 -9a - 27
=(a^3-27)(a^2-2b)
=a^5 - 2a^3b-27a^2+54b
=(a^3-27)(a^2-2b)
=a^5 - 2a^3b-27a^2+54b
2009-01-30 4:24 pm
don't know!
收錄日期: 2021-05-01 11:57:40
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20090130082146AAYB79z