Let the function equal 416 and solve for x.
2x^2 - 6x = 416
2x^2 - 6x - 416 = 0
x^2 - 3x - 208 = 0
(x - 16)(x + 13) = 0
x - 16 = 0 or x + 13 = 0
x = 16 or x = -13
Since the number of rows cannot be negative, discard the -13 solution.
Answer: There are 16 rows.