OE
You know that the area of the rectangular flower bed is 2,400 square feet. So if the flower bed is a feet long and b feet wide, then ab = 2,400. If the side of the flower bed that is bordered by the walkway is one of the sides that are b feet long, then the total length of the three sides of the flower bed bordered by the fence is 2a + b feet. Since you are given that the total length of the fence is 140 feet, it follows that 2a + b = 140. Since ab = 2,400, you can substitute 2,400/a for b in the equation 2a + b = 140 to get the equation \(2a+\frac{2400}{a}=140\) It follows that \(2a^2 + 2,400 = 140a,\) or \(a^2 - 70a + 1,200 = 0.\) When you solve this equation for a (either by factoring or by using the quadratic formula), you get a = 30 or a = 40. If a = 30, then if a = 40, then \(b=\frac{2400}{30} = 80\) then \(b=\frac{2400}{40} = 60\) So the possible lengths of the sides are 30, 40, 60, and 80. Tus the correct answer consists of Choices B, C, E, and G.