Explanation:
36 x 60 is the table
the table cloth extends x inches over every side (x off each side = 2x)
(36 + 2x ) ( 60 + 2x) = 3700 <=== expand to solve
4x^2 + 192 x + 2160 = 3700 re-arrange
4x^2 + 192x - 1540 = 0
Use Quadratic Formula to find x = 7 inches