I have the following maximization problem
$ \max_h m_1 + 10 (h)^{1/4} + h + m_2 - 2 (h)^{1/4} + m_3 - (h)^{1/4} $
where $m_1, m_2, m_3$ are three fixed values. The FOC for a maximum is
$ \dfrac {10}{4} h^{-3/4}+1-\dfrac{1}{2}h^{-3/4}-\dfrac{1}{4}h^{-3/4}=0$
Rearranging
$\dfrac{7}{4} \cdot h^{-3/4} = -1$
Well, now I have no idea... how can I go on? How can I say which level of $h$ maximizes my problem? Of course, I don't want you to solve, but I just would like to get a hint! Thank you in advance!