help please

[AlisaRenae12]

hey can anyone explain how to do this questions

the expression (f(x+h)-f(x))/h for h is not 0 find the simplifed answer to
f(x)=-7x^2+5x+8 ?

 

[mmm4444bot]

To begin, you need to expand everything, and simplify, in the numerator.

Hint: f(x+h) = -7(x+h)^2 + 5(x+h) + 8


Please show us what you get for the simplified numerator. :cool:

 

[AlisaRenae12]

i got -7h^2+5h?

 

[Deleted member 4993]

i got -7h^2+5h?

Not quite....

[-7(x+h)^2 + 5(x+h) + 8] -[-7(x)^2 + 5(x) + 8]

=[-7x^2 - 14xh -7h^2 + 5x + 5h + 8] - [-7(x)^2 + 5(x) + 8]

= -14xh - 7h^2 + 5h

= h * (-14x - 7h + 5)

 

[AlisaRenae12]

ohh ok thank you very much.
but how are you getting the 14xh
are you mult (-7x+-7h)?

 

[Deleted member 4993]

ohh ok thank you very much.
but how are you getting the 14xh
are you mult (-7x+-7h)?

(a + b)² = a² + 2*a*b + b²

 

[mmm4444bot]

are you mult (-7x+-7h)?

As you have shown no multiplication operator in your question above, I cannot understand what you are trying to ask.

Are you trying to ask whether the expression -7x - 7h gets multiplied by something during the process of simplifying the numerator?

Please spell out your future questions by writing complete sentences. Thank you. :cool: