Question 1036959
The Carriage Return is not the thing you want between the x and the 2.



What are you trying to express?
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f(x) = x
2 + 3x + 8. 


 Evaluate and fully simplify f(x + h) − f(x)
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h

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Figuring what you might really want took some time.
f(x)=x^2+3x+8
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Evaluate (f(x+h)-f(x))/h
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Upon rendering tags added,
{{{f(x)=x^2+3x+8}}}
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Evaluate {{{(f(x+h)-f(x))/h}}}



Form the parts of the Difference Quotient into place.
The start of that looks like this:    {{{((x+h)^2+3(x+h)+8-(x^2+3x+8))/h}}}.


Now the task to do is to simplify this Difference Quotient.