The function

is defined as follows :

Basically, you are trying to simplify this :

,

It is equivalent to (by substituting the function into your expression) :

,

Expand this :

,

Further expansion required ...

,

Simplify :

> get rid of the constants (150, 130, 20, ...), they cancel out (who would have guessed it ?).

> simplify the linear coefficients (60h - 4h) !

> reorganize the equation, looks better ...

,

Factorize with

:

,

Finally, cancel out the

, to find :

And you are done

EDIT : ah Defunkt you win, I was busy checking my reply :/