Let x= number rows Then x + 5 = number of seats per row
x(x+5) = 126 X^2 + 5x = 126 x^2 + 5x -126 = 0; now factor or use quadratic: (x+14)(x-9) = 0; so the answers are either -14, or 9, and since -14 is not possible in this case because you can't have a negative number of rows, the answer is 9 rows.
Check work: number of rows = 9, number of seats per row = 9+ 5= 14, and 9 x 14 = 126
