Question 512919
<pre>
         c = 67s + 5000 

   Since c = $105000, we substitute (ignoring the dollar mark)

    105000 = 67s + 5000 

Swap right and left sides:

67s + 5000 = 105000

Subtract 5000 from both sides

       67s = 100000

Divide both sides by 67

         s = 1492.537313, approximately 1500 

That tells us that a home with approximately 
1500 square feet of floor space can be built 
for $105,000. 

Edwin</pre>