To add the polynomials \( (3x^4 - 2x - 7) + (-4 + 5x^2 - 3x + x^4) \), we start by combining like terms.
First, let's rewrite the expression clearly:
\[ 3x^4 - 2x - 7 - 4 + 5x^2 - 3x + x^4 \]
Now we regroup the like terms based on their degrees:
- The \(x^4\) terms: \(3x^4 + x^4\)
- The \(x^2\ terms: (5x^2\)
- The \(x\ terms: (-2x - 3x\)
- The constant terms: \(-7 - 4\)
Now, let's combine each group:
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For \(x^4\) terms: \[ 3x^4 + x^4 = 4x^4 \]
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For \(x^2\) terms: \[ 5x^2 \]
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For \(x\) terms: \[ -2x - 3x = -5x \]
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For constant terms: \[ -7 - 4 = -11 \]
Combining all these results, we have:
\[ 4x^4 + 5x^2 - 5x - 11 \]
Thus, the sum of the polynomials is:
\[ \boxed{4x^4 + 5x^2 - 5x - 11} \]