To find \((f + g + h)(x)\), we first need to explicitly express each function:
- \( f(x) = -x^4 + 7x^2 + 6 \)
- \( g(x) = |x - 7| + 1 \)
- \( h(x) = \sqrt{x + 3} - 8 \)
Now, we combine them:
\[ (f + g + h)(x) = f(x) + g(x) + h(x) \] \[ = (-x^4 + 7x^2 + 6) + (|x - 7| + 1) + (\sqrt{x + 3} - 8) \]
Combining these, we get:
\[ (f + g + h)(x) = -x^4 + 7x^2 + |x - 7| + \sqrt{x + 3} + (6 + 1 - 8) \] \[ = -x^4 + 7x^2 + |x - 7| + \sqrt{x + 3} - 1 \]
Next, we need to find the domain of \((f + g + h)(x)\):
- The function \(f(x) = -x^4 + 7x^2 + 6\) is a polynomial and is defined for all real numbers.
- The function \(g(x) = |x - 7| + 1\) is also defined for all real numbers.
- The function \(h(x) = \sqrt{x + 3} - 8\) requires that \(x + 3 \geq 0\), which means \(x \geq -3\).
Thus, the overall domain of \((f + g + h)(x)\) is determined by the function \(h(x)\), which gives us:
\[ \text{Domain: } x \geq -3 \]
Therefore, the final result is:
\[ (f + g + h)(x) = -x^4 + 7x^2 + |x - 7| + \sqrt{x + 3} - 1 \] and the domain of \((f + g + h)(x)\) is \(x \geq -3\).