the area of the border is the total area less the vegetable area, so
if the border has width x, then you need
6*12 - (6-2x)(12-2x) = 40
now just solve for x as usual
A vegetable gardener has a tilled piece of soil that measures 6 yards by 12 yards. She wants to put a border of marigolds of the same width within the four sides and leave an area of 40 square yards for vegetables. How wide can the border be?
1 answer