Originally Posted by

**topsquark** One quick question. I know that 5,5 is 5.5 in other places. But what does this mean? "1/1,0"? It looks like you are dividing 1 by 1 but why put it as 1/1,0?

Assuming that 1/1,0 = 1, then

$\displaystyle 275 \frac{5,5-\frac{h}{30}}{3} \cdot \frac{30*h^2}{6} = 288 \times 10^3$

Mulitply both sides by 18:

$\displaystyle 275 \left ( 5,5-\frac{h}{30} \right ) \cdot ( 30*h^2 ) = 18 \cdot 288 \times 10^3$

Multiply out the LHS:

$\displaystyle 275 \left ( 5,5-\frac{h}{30} \right ) \cdot ( 30*h^2 ) = 18 \cdot 288 \times 10^3$

$\displaystyle 275(165h^2 - h^3) = 5184 \times 10^3 = 5,184 \times 10^6$

This is evidently not the equation you were supposed to derive, but the method to solve it will be the same.

-Dan