Question 260299
First, we have f(x) = 3x + 7.
second, We need to find f(x+h).
f(x+h) = 3(x+h) + 7 = 3x + 3h + 7
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Now we can find {{{(f(x+h) -f(h))/h}}} as
{{{(f(x+h) -f(h))/h}}}  = {{{((3x+3h+7)-(3x+7))/h}}}
notice what happens in the numerator . . . the 3x + 7 will drop out. This will always happen. We get
{{{(f(x+h) -f(h))/h}}}  = 3h/h
Now, h approaches 0, so we end with
{{{(f(x+h) -f(h))/h}}} = 3.
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