318Views9Replies

Author Options:

how do I factor c cubed + 27?? Answered


Tags:Math

Comments

The forums are retiring in 2021 and are now closed for new topics and comments.
0
kiffer360
kiffer360

11 years ago

c^3+27
addition of cubes
(c+3)(c^2+3c+9) 

Am I reading the problem wrong?

0
seandogue
seandogue

Answer 11 years ago

No, but your answer is wrong. close, but wrong.

0
kiffer360
kiffer360

Answer 11 years ago

right, its the formula. i never can rember the correct formula. (c+3)(c2-3c+9) i think. 

0
seandogue
seandogue

Answer 11 years ago

Ding!...  I guess I'd forgotten that there's a formula for disemboweling a cubic equation. I played the "guess the first term" game...

0
NobodyInParticular
NobodyInParticular

11 years ago

 I suspect that you were supposed to memorize the factorizations of the sum of cubes, difference of cubes, difference of squares, and perfect square trinomials. If you memorize these, you will save yourself a great deal of trouble.

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


0
seandogue
seandogue

11 years ago

Perhaps start by thinking of it as a disguised quadratic instead of a cubic equation?