Question 1171110
<br>
No doubt a formal algebraic solution was expected for this problem.<br>
However, note that solving the problem using logical reasoning and simple arithmetic (and, in this case, some common sense estimation) can be give good problem-solving experience.<br>
The border will need to have strips along each of the four sides of the pool, which means along the whole perimeter, a distance of 2(30+40) = 140 feet.<br>
We can estimate the width of the border by dividing the given 296 square feet of material by the perimeter of 140 feet to see that the width of the border will be about 2 feet.<br>
The 2-foot border along all sides of the pool will use 140*2=280 square feet of the material.<br>
And there will be square portions of the border at each corner of the pool that are each 2*2=4 square feet.<br>
But 280 square feet of material along the edges of the pool, plus four corners of 4 square feet each makes exactly the 296 square feet we have.  So<br>
ANSWER: The border can be 2 feet wide.<br>