Question

Hopefully someone can help? Thanks

Answer 1

2x + h - 7

Explanation:

`(f(x+h)-f(x))/(h)` ← substitute x = x+ h into f(x)

=
`((x+h)^2-7(x+h)+9-(x^2-7x+9))/(h)` ← expand (x + h)² using FOIL

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`(x^2+2hx+h^2-7x-7h+9-x^2+7x-9)/(h)` ← collect like terms

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`(2hx+h^2-7h)/(h)` ← factor out h from each term on the numerator

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`(h(2x+h-7))/(h)` ← cancel h on numerator/ denominator

= 2x + h - 7