Which of the following is a correct way to rewrite the expression x^4 + 18x^2 + 81

A
[(x + 3)(x – 3)]^2

B
(x + 9)^2

C
(x^2 + 9)^2

D
(x + 3)^4

E
(x^2 + 3)^4

x^4 + 18x^2 + 81 =
(x^2 + 9)^2
Answer is C.

Dear Hearts:(,

x^(4)+18x^(2)+81

In this problem 9*9=81 and 9+9=18, so insert 9 as the right hand term of one factor and 9 as the right-hand term of the other factor.
(x^(2)+9)(x^(2)+9)

Combine the two common factors of (x^(2)+9) by adding the exponents.
(x^(2)+9)^(2) so "c" is your answer
=======================
Who am I, ldiazmdiaz, learn more...
http://www.youtube.com/results?search_qu…
=======================
Thanks

The answer is option C : (x^2 + 9)^2
The expansion of this is x^4 + 18x^2 + 81

c