SOLUTION: Evaluate [f(x+h)-f(x)]/h and simplify if f(x)=x^2-2x Help please!

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Question 473000: Evaluate [f(x+h)-f(x)]/h and simplify if f(x)=x^2-2x
Help please!
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
f(x)=x^2-2x


f(x+h)=(x+h)^2-2(x+h)


f(x+h)=x^2+2xh+h^2-2x-2h


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[f(x+h)-f(x)]/h


[(x^2+2xh+h^2-2x-2h)-(x^2-2x)]/h


[x^2+2xh+h^2-2x-2h-x^2+2x]/h


[2xh+h^2-2h]/h


[h(2x+h-2)]/h


2x+h-2


2x-2+h


So [f(x+h)-f(x)]/h = 2x-2+h when f(x)=x^2-2x