Question

Factor completely 9x4 + 12x3 + 21x2.

Answer 1

Answer:

The factor of $9 x^{4}+12 x^{3}+21 x^{2} \text { is } 3 x^{2}\left(3 x^{2}+4 x+7\right)$

Solution:

From question given that the equation is

$9 x^{4}+12 x^{3}+21 x^{2}$

We have to find the factors of the given equation.

By taking 3 as a common term in above expression,

$=3\left(3 x^{4}+4 x^{3}+7 x^{2}\right)$

By taking “x” as a common term in above expression, we get equation as

$=3 x\left(3 x^{3}+4 x^{2}+7 x\right)$

Again taking “x” as a common term in above expression, we get

$=3 x^{2}\left(3 x^{2}+4 x+7\right)$

$\left(3 x^{2}+4 x+7\right)$ cannot be factorized.(imaginary roots)

Hence factor of $9 x^{4}+12 x^{3}+21 x^{2} \text { is } 3 x^{2}\left(3 x^{2}+4 x+7\right)$

Answer 2

Answer:

the answer is (C) 3x(x^2-5)(3x+4).

Step-by-step explanation: