Math help

[Xenus]

I can't find out how to simplify this:
For g(u)= 8/(9x-2) find and simplify ( g (x+h) - g (x) ) / h

 

[Mintmaster]

Sub it all in and multiply the numerator and denominator by [9(x + h) - 2](9x - 2).

In the numerator you'll eventually wind up with 8[(9x + 9h - 2) - (9x - 2)], which is actually just -72h.

I assume you'll eventually take h to 0 (just starting calculus, right?), and in the denominator you'll have (9x - 2)^2.

I hope you weren't hoping for a hint rather than an outright answer!

 

[Xenus]

You lost me is it -72/(9x-2)^2 beacuse that doesn't seem right

Edit got it -72/(81(x^2)+(81hx)-(36x)-(18h)+4)