Questions: Factor the polynomial completely using the grouping method.
21x-4+18x^2
21x-4+18x^2=
Transcript text: Factor the polynomial completely using the grouping method.
\[
\begin{array}{l}
21 x-4+18 x^{2} \\
21 x-4+18 x^{2}=
\end{array}
\]
Solution
Solution Steps
To factor the polynomial \( 21x - 4 + 18x^2 \) completely using the grouping method, we need to rearrange the terms and group them in pairs that can be factored easily.
Rearrange the polynomial in standard form: \( 18x^2 + 21x - 4 \).
Group the terms in pairs: \( (18x^2 + 21x) + (-4) \).
Factor out the greatest common factor (GCF) from each group.
Look for a common binomial factor.
Step 1: Rearranging the Polynomial
We start with the polynomial \( 21x - 4 + 18x^2 \). Rearranging it in standard form gives us:
\[
18x^2 + 21x - 4
\]
Step 2: Grouping the Terms
Next, we group the polynomial into two parts:
\[
(18x^2 + 21x) + (-4)
\]
Step 3: Factoring Each Group
Now, we factor out the greatest common factor (GCF) from each group:
\[
3x(6x + 7) - 4
\]
Step 4: Finding Common Factors
We can rewrite the expression as:
\[
3x(6x + 7) - 4(1)
\]
This does not yield a common binomial factor directly, so we can factor the entire polynomial as:
\[
(3x + 4)(6x - 1)
\]
Final Answer
Thus, the completely factored form of the polynomial \( 21x - 4 + 18x^2 \) is:
\[
\boxed{(3x + 4)(6x - 1)}
\]