The rectangle below has an area of x^2+8x+15x
2
+8x+15x, squared, plus, 8, x, plus, 15 square meters and a width of x+3x+3x, plus, 3 meters.
What expression represents the length of the rectangle?

David and alton are training for a race. they spend 35 minutes stretching and then go on a 5 mile practice run. david runs at a pace of 7 min/mile. alton runs at a pace of 8 min/mile. write an equation for each runner that shows the total length of their workout. then solve each equation showing your work