I'm trying to solve the following set of equations, I'm trying to work out how to put them into matrix form to solve, but I can't see how to.

$\displaystyle

\begin{array}{l}

B_1 = \frac{{1.5H_1 }}{{100 + H_1 }} \\

B_2 = \frac{{1.5H_2 }}{{100 + H_2 }} \\

1000 = H_1 \times 0.25 + H_2 \times 0.5 \\

\left( {25 \times 10^{ - 4} } \right)B_1 = (12.5 \times 10^{ - 4} )B_2 \\

\end{array}

$