Which of these is a correct expansion of [tex]$(3x - 2)(2x^2 + 5)$[/tex]?

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

B. [tex]3x \cdot 2x^2 + 3x \cdot 5 + 2 \cdot 2x^2 + 2 \cdot 5[/tex]

C. [tex]3x \cdot 2x^2 + 3x \cdot 5 + (-2) \cdot 2x^2 + (-2) \cdot 5[/tex]



Answer :

The question asks for the correct expansion of [tex]\((3x - 2)(2x^2 + 5)\)[/tex]. To solve this, we'll apply the distributive property (also known as the FOIL method for binomials).

The distributive property states that [tex]\((a + b)(c + d) = ac + ad + bc + bd\)[/tex], which means we need to multiply each term in the first parenthesis by each term in the second parenthesis.

For [tex]\((3x - 2)(2x^2 + 5)\)[/tex], let's proceed step by step:

1. Multiply [tex]\(3x\)[/tex] by [tex]\(2x^2\)[/tex]:
[tex]\[ 3x \cdot 2x^2 = 6x^3 \][/tex]

2. Multiply [tex]\(3x\)[/tex] by [tex]\(5\)[/tex]:
[tex]\[ 3x \cdot 5 = 15x \][/tex]

3. Multiply [tex]\(-2\)[/tex] by [tex]\(2x^2\)[/tex]:
[tex]\[ -2 \cdot 2x^2 = -4x^2 \][/tex]

4. Multiply [tex]\(-2\)[/tex] by [tex]\(5\)[/tex]:
[tex]\[ -2 \cdot 5 = -10 \][/tex]

Putting all these terms together, we have the expanded form:
[tex]\[ 6x^3 + 15x - 4x^2 - 10 \][/tex]

Now, we need to verify which of the given statements matches this expansion process:

A. [tex]\(3x \cdot 2x^2 + (-2) \cdot 2x^2 + 2x^2 \cdot 5 + (-2) \cdot 5\)[/tex]
B. [tex]\(3x \cdot 2x^2 + 3x \cdot 5 + 2 \cdot 2x^2 + 2 \cdot 5\)[/tex]
C. [tex]\(3x \cdot 2x^2 + 3x \cdot 5 + (-2) \cdot 2x^2 + (-2) \cdot 5\)[/tex]

Comparing these options step-by-step:

- Option A incorrectly includes [tex]\(2x^2 \cdot 5\)[/tex].
- Option B incorrectly uses [tex]\(2\)[/tex] instead of [tex]\(-2\)[/tex].
- Option C correctly matches each term.

Thus, the correct option is:
[tex]\[ \boxed{\text{C}} \][/tex]