Question 1138779
how long the front of the house may be refers to how wide is it, i believe.


since the lot is 91 feet wide and you cannot build closer than 10 feet from the lot line on either side, then the width of the house can be no greater than 91 - 20 = 71 feet long.


here's my diagram.


the house is the little rectangle in the middle.


<img src = "http://theo.x10hosting.com/2019/041011.jpg" alt="$$$" >


if you let W equal the width of the house, then the inequality would be:


W <= 71


that's because the width of the lot is 91 and you have to be 10 feet from either side of the lot line, which means the width of the house has to be 20 feet less than 91 which is equal to 71.


if the width of the lot was unknown, and you let L equal the width of the lot, then the inequality would be:


W <= L - 20


when L = 91, the formula becomes W <= 91 - 20 which becomes W <= 71.