Question 526267
the cost for a window is ___ .50 + .50f , where f is the floor


the average cost per window for n stories (floors) is ___ [(1st floor) + (nth floor)] / 2


the total cost for n stories is 24n times the average ___ 24n[1 + (.50 + .50n)] / 2


12n(1.50 + .50n) ___ 18n + 6n^2