To solve for h first add all similar terms, in this case, those with h:
[tex]\begin{gathered} h+3h+4h=100 \\ 8h=100 \end{gathered}[/tex]Now, divide by 8 into both sides of the equation
[tex]\begin{gathered} \frac{8h}{8}=\frac{100}{8} \\ h=\frac{100}{8} \end{gathered}[/tex]Finally, simplify
[tex]\begin{gathered} h=\frac{25\cdot4}{2\cdot4} \\ h=\frac{25}{2} \end{gathered}[/tex]Therefore, the value of h is
[tex]\begin{gathered} h=\frac{25}{2} \\ \text{ or} \\ h=12.5 \end{gathered}[/tex]