Can someone factor this? --8x^3 + 27 ( Eight X to the third + 27)?

👨🏻‍🏫 學術台數學

[匿名]

2008-09-21 4:33 pm

I know it is a perfect cube but I forget how to factor it.

回答 (3)

[匿名]

2008-09-21 4:44 pm

✔ 最佳答案

(2x)^3 + 3^3

(2x + 3)^3

👍 0 👎 1

An ESL Learner

2008-09-21 11:48 pm

a^3 + b^3 = (a + b)(a^2 - ab + b^2)

8x^3 + 27
= (2x)^3 + 3^3
= [2x + 3][(2x)^2 - 6x + 3^2]
= [2x + 3][4x^2 - 6x + 9]

👍 1 👎 0

None

2008-09-22 12:16 am

8x^3 + 27 = (2x)^3 + 3^3 = (2x + 3)(4x^2 - 6x + 9)

x3 + y3 = (x+y)(x2-xy+y2)

👍 0 👎 0