Question 1198707
This example or others like it were solved several times before on this site.
<pre>
TYPE              PRICE        QUANTITY            COSTS

Main               44           43+(270+2z+z)

Mezzanine          36                z

Balcony            38          270+2z

TOTALS                                               47456
</pre>
A few small simplifications can be done.  Form the cost equation in one single variable, z.  Solve...