Question 1106540
This is a matter of substituting and simplifying.

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d) f(x) = x^2 - x - 1 
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{{{(f(2+h)-f(2))/h}}}----this is the model expression you showed, but only grouping symbols included here for the adjustment.


Make the substitution:

{{{((2+h)^2-(2+h)-1-(2^2-2-1))/h}}}

and then simplification,...


{{{(4+4h+h^2-2-h-1-1)/h}}}

-

{{{(4+4h+h^2-2-h-2)/h}}}


{{{(4-2-2+4h+h^2-h)/h}}}

{{{(4h-h+h^2)/h}}}

{{{(3h+h^2)/h}}}

{{{(3+h)(h/h)}}}

{{{3+h}}}

{{{highlight(h+3)}}}





The following was a MISTAKE ,...
{{{(4h+h^2)/h}}}

{{{cross(4+h)}}}