Simplify the following expression:

[tex]\[ x^4 + 3x^3 - 2x^3 - 5x^2 - x + x^2 + x + 1 + 7x^4 \][/tex]

A. \( 8x^4 + x^3 - 4x^2 + 0x \)
B. \( 8x^4 + 5x^3 + 4x^2 + 1 \)
C. \( 8x^4 + x^3 - 4x^2 + 1 \)
D. [tex]\( 8x^4 + 5x^3 + 4x^2 + 0x + 1 \)[/tex]



Answer :

Let's simplify the given expression step-by-step:

Given expression:
[tex]\[ x^4 + 3x^3 - 2x^3 - 5x^2 - x + x^2 + x + 1 + 7x^4 \][/tex]

1. Combine like terms:

[tex]\[ x^4 + 7x^4 \][/tex]

This results in:
[tex]\[ 8x^4 \][/tex]

Next, we look at the \(x^3\) terms:
[tex]\[ 3x^3 - 2x^3 \][/tex]

This simplifies to:
[tex]\[ x^3 \][/tex]

Now we combine the \(x^2\) terms:
[tex]\[ -5x^2 + x^2 \][/tex]

This simplifies to:
[tex]\[ -4x^2 \][/tex]

Next, we combine the \(x\) terms:
[tex]\[ -x + x \][/tex]

This results in:
[tex]\[ 0x \][/tex]

Finally, we have the constant term:
[tex]\[ +1 \][/tex]

2. Combine all simplified terms:
[tex]\[ 8x^4 + x^3 - 4x^2 + 1 \][/tex]

From the provided multiple-choice options, this matches option C.

So, the simplified expression is:
[tex]\[ \boxed{8x^4 + x^3 - 4x^2 + 1} \][/tex]

Therefore, the correct answer is:
[tex]\[ \boxed{\text{C. } 8x^4 + x^3 - 4x^2 + 1} \][/tex]