The garden and a walkway around its perimeter have an area of 868. Find the width of the walkway if the garden measures 12 feet wide by 15 feet long.

Answer 1

The area of the garden is 180.

So the area of the walkway is 868-180 = 688

Let w be the width of the walkway.

The area of the walkway is 2(15w) <----- lengthwise

+ 2(12w) <---- height wise

+ 4*w^2 <--- 4 corners

= 30w + 24w + 4w^2 = 688

4w^2 + 54w - 688 = 0

2w^2 + 27w - 344 = 0

(2w + 43 )(w - 8 ) = 0

w=8 is the only positive solution