$\"\"$

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The function $\"f\\left$ .

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Find $\"\"$ $\"f\\left$ .

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Substitute $\"x=a\"$ in $\"f\\left$ .

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$\"f\\left$ .

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$\"\"$

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Find $\"f\\left$ .

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Substitute $\"x=a+h\"$ in $\"f\\left$ .

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$\"f\\left$

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$\"f\\left$ .

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$\"\"$

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Find $\"\\frac{f\\left$ .

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Substitute the values of $\"f\\left$ and $\"f\\left$ .

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$\"\\frac{f\\left$

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$\"=\\frac{2(5-a)-2(5-a-h)}{h(5-a-h)(5-a)}\"$

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$\"=\\frac{10-2a-10+2a+2h}{h(5-a-h)(5-a)}\"$

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$\"=\\frac{2h}{h(25-5a-5a+a^2-5h+ah)}\"$

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$\"\\frac{f(a+h)-f(a)}{h}=\\frac{2}{a^2-10a+ah-5h+25}\"$ .

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$\"\"$

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$\"f\\left$ .

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$\"f\\left$ .

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$\"\\frac{f(a+h)-f(a)}{h}=\\frac{2}{a^2-10a+ah-5h+25}\"$ .