Completely factor [tex][tex]$25 x^4 + 10 x^3 + 5 x^2 + 2 x$[/tex][/tex].

A. [tex][tex]$x\left(5 x^2 + 2\right)$[/tex][/tex]

B. [tex][tex]$x\left(5 x^2 + 2\right)(2 x + 1)$[/tex][/tex]

C. [tex][tex]$x\left(5 x^2 + 1\right)(5 x + 2)$[/tex][/tex]

D. [tex][tex]$x(5 x + 1)\left(5 x^2 + 2\right)$[/tex][/tex]



Answer :

To factor the polynomial [tex]\( 25x^4 + 10x^3 + 5x^2 + 2x \)[/tex] completely, we need to follow a systematic approach.

1. Identify and factor out the greatest common factor (GCF):

The polynomial [tex]\( 25x^4 + 10x^3 + 5x^2 + 2x \)[/tex] has the GCF of [tex]\( x \)[/tex], since each term contains at least one [tex]\( x \)[/tex]. Factor [tex]\( x \)[/tex] out:

[tex]\[ 25x^4 + 10x^3 + 5x^2 + 2x = x (25x^3 + 10x^2 + 5x + 2) \][/tex]

2. Analyze the cubic polynomial inside the parentheses:

Next, we want to factor the cubic polynomial [tex]\( 25x^3 + 10x^2 + 5x + 2 \)[/tex]. We start by trying to group the terms in a way that can facilitate further factoring.

Observe that this polynomial does not have a common factor among all its terms, but we can attempt to factor by grouping or use known factorization techniques.

3. Attempt further factorization of the cubic polynomial:

We notice that [tex]\( 25 \)[/tex] can be expressed as [tex]\( 5^2 \)[/tex]. Let’s look for possible binomial factors:

We can test out some potential pairs:

[tex]\( 25x^3 + 10x^2 + 5x + 2 = (ax + b)(cx^2 + dx + e). \)[/tex]

After careful consideration and comparing coefficients, we find that it factors nicely into:

[tex]\[ 25x^3 + 10x^2 + 5x + 2 = (5x + 2)(5x^2 + 1) \][/tex]

4. Complete the factorization:

Combining our factored terms, we have:

[tex]\[ 25x^4 + 10x^3 + 5x^2 + 2x = x(5x + 2)(5x^2 + 1) \][/tex]

Hence, the completely factored form of [tex]\( 25x^4 + 10x^3 + 5x^2 + 2x \)[/tex] is:

[tex]\[ x(5x + 2)(5x^2 + 1) \][/tex]