What is the factored form of the expression [tex]\( 9x^2 + 6x + 1 \)[/tex]?

A. [tex]\( (3x - 1)^2 \)[/tex]
B. [tex]\( (3x + 1)^2 \)[/tex]
C. [tex]\( (9x + 1)^2 \)[/tex]
D. [tex]\( (9x - 1)^2 \)[/tex]



Answer :

To factor the quadratic expression [tex]\(9x^2 + 6x + 1\)[/tex], we need to determine what the expression simplifies to when written in the form of [tex]\((ax + b)^2\)[/tex]. Follow these steps:

1. Recognize the standard form of a quadratic expression:
[tex]\[ ax^2 + bx + c \][/tex]
Here, [tex]\( a = 9 \)[/tex], [tex]\( b = 6 \)[/tex], and [tex]\( c = 1 \)[/tex].

2. Set up the factored form as [tex]\((dx + e)^2\)[/tex] and expand it:
[tex]\[ (dx + e)^2 = d^2x^2 + 2dex + e^2 \][/tex]

3. Compare coefficients:
- The coefficient of [tex]\(x^2\)[/tex] in [tex]\((dx + e)^2\)[/tex] should match [tex]\(9x^2\)[/tex] from the original expression.
- Hence, [tex]\( d^2 = 9 \)[/tex] which gives [tex]\( d = 3 \)[/tex] (since [tex]\(3^2 = 9\)[/tex]).
- The constant term [tex]\(e^2\)[/tex] should match [tex]\(1\)[/tex].
- Therefore, [tex]\( e^2 = 1 \)[/tex] which gives [tex]\( e = 1 \)[/tex] (since [tex]\(1^2 = 1\)[/tex]).

4. The middle term [tex]\(2dex\)[/tex] of the expanded form should match the middle term [tex]\(6x\)[/tex] of the original expression.
[tex]\[ 2(3)(1)x = 6x \][/tex]

Given these comparisons, the correct factorized form of the quadratic expression [tex]\(9x^2 + 6x + 1\)[/tex] is therefore:
[tex]\[ (3x + 1)^2 \][/tex]

So, the correct answer is:
[tex]\[ (3x + 1)^2 \][/tex]

Other Questions