Select the correct answer from each drop-down menu. Consider the expressions given below:

A. [tex]2x^3 - x^2 - 6x[/tex]
B. [tex]2x^3 + 8x + 4[/tex]
C. [tex]3x^4 + x^2 + x - 7[/tex]
D. [tex]3x^4 - 3x^2 + 5x - 7[/tex]

For each expression below, select the letter that corresponds to the equivalent expression from the given list.

1. [tex](4x^3 - 4 + 7x) - (2x^3 - x - 8)[/tex] is equivalent to expression [tex]\square[/tex]

2. [tex](-3x^2 + x^4 + x) + (2x^4 - 7 + 4x)[/tex] is equivalent to expression [tex]\square[/tex]

3. [tex](x^2 - 2x)(2x + 3)[/tex] is equivalent to expression [tex]\square[/tex]



Answer :

Let's break down each expression and compare it to the choices given.

1. For the expression [tex]\((4x^3-4+7x) - (2x^3-x-8)\)[/tex]:

- First, simplify inside the parentheses:
[tex]\[ (4x^3 - 4 + 7x) - (2x^3 - x - 8) \][/tex]

- Distribute the negative sign:
[tex]\[ = 4x^3 - 4 + 7x - 2x^3 + x + 8 \][/tex]

- Combine like terms:
[tex]\[ = (4x^3 - 2x^3) + (7x + x) + (-4 + 8) \][/tex]
[tex]\[ = 2x^3 + 8x + 4 \][/tex]

- Comparing this with the given choices:
[tex]\[ 2x^3 + 8x + 4 \quad \text{corresponds to B} \][/tex]

2. For the expression [tex]\((-3x^2 + x^4 + x) + (2x^4 - 7 + 4x)\)[/tex]:

- Combine like terms within the parentheses:
[tex]\[ = (-3x^2 + x^4 + x) + (2x^4 - 7 + 4x) \][/tex]

- Combine the expressions:
[tex]\[ = x^4 + 2x^4 - 3x^2 + x + 4x - 7 \][/tex]

- Simplify further:
[tex]\[ = (x^4 + 2x^4) + (-3x^2) + (x + 4x) - 7 \][/tex]
[tex]\[ = 3x^4 - 3x^2 + 5x - 7 \][/tex]

- Comparing this with the given choices:
[tex]\[ 3x^4 - 3x^2 + 5x - 7 \quad \text{corresponds to D} \][/tex]

3. For the expression [tex]\((x^2 - 2x)(2x + 3)\)[/tex]:

- Use the distributive property:
[tex]\[ (x^2 - 2x)(2x + 3) \][/tex]

- Apply the distributive property:
[tex]\[ = x^2 \cdot 2x + x^2 \cdot 3 - 2x \cdot 2x - 2x \cdot 3 \][/tex]

- Simplify each term:
[tex]\[ = 2x^3 + 3x^2 - 4x^2 - 6x \][/tex]

- Combine like terms:
[tex]\[ = 2x^3 + (3x^2 - 4x^2) - 6x \][/tex]
[tex]\[ = 2x^3 - x^2 - 6x \][/tex]

- Comparing this with the given choices:
[tex]\[ 2x^3 - x^2 - 6x \quad \text{corresponds to A} \][/tex]

So, the expressions correspond to:
1. [tex]\( (4x^3 - 4 + 7x) - (2x^3 - x - 8) \)[/tex] is equivalent to expression B.
2. [tex]\( (-3x^2 + x^4 + x) + (2x^4 - 7 + 4x) \)[/tex] is equivalent to expression D.
3. [tex]\( (x^2 - 2x)(2x + 3) \)[/tex] is equivalent to expression A.