Question

Marge wants to build a sidewalk of uniform width around a rectangular swimming pool that is 80 feet long and 50 feet wide.she has 2000 square feet of concrete to create the sidewalk.what should be the width of the sidewalk

Answer 1

For this case, the first thing we are going to do is rewrite the expression of the pool area again.
 We have then:
 (80 + 2W) (50 + 2W) - 80 (50) = 2,000
 Rewriting we have:
 4000 + 160W + 100W + 4W ^ 2 - 4000 = 2000
 4W ^ 2 + 260W - 2000 = 0
 W1 = 6.949334595148748
 W2 = -71.94933459514874 (ignore)
 round:
 W = 6.95
 Answer:
 the width of the sidewalk should be:
 W = 6.95 feet