$\"\"$

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The functions are f(x) = x + 9 and g(x) = x $\"\"$ 9.

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a) (f + g)(x)

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$\"open$

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$\"equal$ (Substitute f(x) = x + 9 and g(x) = x $\"\"$ 9)

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$\"equal$

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$\"equal$

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$\"\"$

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b) (f $\"\"$ g)(x)

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$\"open$

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$\"equal$ (Substitute f(x) = x + 9 and g(x) = x $\"\"$ 9)

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$\"equal$

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$\"equal$

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$\"\"$

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c) $\"open$

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$\"open$

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$\"equal$ (Substitute f(x) = x + 9 and g(x) = x $\"\"$ 9)

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$\"equal$

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$\"equal$

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$\"equal$

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$\"equal$

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$\"\"$

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d) $\"open$

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$\"open$

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$\"equal$ (Substitute f(x) = x + 9 and g(x) = x $\"\"$ 9)

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$\"x$

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Because x = 9 then $\"x$ , 9 is excluded from the domain of $\"open$ . $\"\"$

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(f + g)(x) $\"equal$ , (f $\"\"$ g)(x) $\"equal$ , $\"open$ $\"equal$ and $\"open$ $\"equal$ .