Solve the following expression:

[tex]\[
(2x + 5)(3x^2 + 2x - 1)
\][/tex]

Choose the correct expansion:

A. [tex]\(6x^3 + 19x^2 + 8x - 5\)[/tex]

B. [tex]\(6x^3 + 11x^2 + 8x + 5\)[/tex]

C. [tex]\(5x^3 + 19x^2 + 8x + 5\)[/tex]

D. [tex]\(6x^3 + 19x^2 + 12x - 5\)[/tex]



Answer :

Certainly! Let's multiply the two given polynomials step by step:

The given problem is to multiply the polynomials [tex]\((2x + 5)\)[/tex] and [tex]\((3x^2 + 2x - 1)\)[/tex].

### Step-by-Step Solution:

1. Distribute [tex]\(2x\)[/tex] across each term in the second polynomial:
[tex]\[ 2x \cdot (3x^2) + 2x \cdot (2x) + 2x \cdot (-1) \][/tex]
- [tex]\(2x \cdot 3x^2 = 6x^3\)[/tex]
- [tex]\(2x \cdot 2x = 4x^2\)[/tex]
- [tex]\(2x \cdot (-1) = -2x\)[/tex]

So, the result of distributing [tex]\(2x\)[/tex] is:
[tex]\[ 6x^3 + 4x^2 - 2x \][/tex]

2. Distribute [tex]\(5\)[/tex] (the constant term) across each term in the second polynomial:
[tex]\[ 5 \cdot (3x^2) + 5 \cdot (2x) + 5 \cdot (-1) \][/tex]
- [tex]\(5 \cdot 3x^2 = 15x^2\)[/tex]
- [tex]\(5 \cdot 2x = 10x\)[/tex]
- [tex]\(5 \cdot (-1) = -5\)[/tex]

So, the result of distributing [tex]\(5\)[/tex] is:
[tex]\[ 15x^2 + 10x - 5 \][/tex]

3. Combine all the terms obtained from both distributions:
[tex]\[ 6x^3 + 4x^2 - 2x + 15x^2 + 10x - 5 \][/tex]

4. Combine like terms:
[tex]\[ \begin{aligned} 6x^3 & : \text{This term has no like term, so it remains } 6x^3. \\ 4x^2 + 15x^2 & : Combine the \(x^2\) terms: \(4x^2 + 15x^2 = 19x^2\). \\ -2x + 10x & : Combine the \(x\) terms: \(-2x + 10x = 8x\). \\ -5 & : The constant term remains \(-5\). \end{aligned} \][/tex]

5. Write the final expression combining all the simplified terms:
[tex]\[ 6x^3 + 19x^2 + 8x - 5 \][/tex]

Therefore, the final result of multiplying [tex]\((2x + 5)\)[/tex] with [tex]\((3x^2 + 2x - 1)\)[/tex] is:
[tex]\[ \boxed{6x^3 + 19x^2 + 8x - 5} \][/tex]