I have come up against a question in a past paper I am revising for a maths exam next week and I am having some difficulty.
The question is:
A concrete path with uniform width x metres is to be built around the rectangular base of a house of length 61 metres and width 35 metres. The area of the path is 400m^2. Set up a quadratic equation in x and solve it to give the width of the path.
So far I have: