SOLUTION: Suppose f(x) = x^2 + 9x. Simplify f(x + h)- f(x) / h .

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Question 306128: Suppose f(x) = x^2 + 9x. Simplify f(x + h)- f(x) / h .
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Suppose f(x) = x^2 + 9x. Simplify f(x + h)- f(x) / h .
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f(x+h) = (x+h)^2 + 9(x+h) = x^2 + 2hx + h^2 + 9x + 9h
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f(x+h)-f(x) = 2hx +h^2+9h
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Finally:
f(x + h)- f(x) / h = 2x + h + 9
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Cheers,
Stan H
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