Answer:
17 rows
Step-by-step explanation:
We know that f(x) = 2x² - 10x models the total number of spaces and x models the number of rows.
Since we are given the total number of spaces of 408. We let f(x) = 408
2x² - 10x = 408
Now we solve as a quadratic, subtract 408 to both sides
2x² - 10x - 408 = 0
Divide 2 on both sides
x² - 5x - 204 = 0
We look for terms that multiply to -204 and add to -5.
Those terms are -17 and 12
x² - 17x + 12x - 204 = 0
x(x-17) + 12(x-17)
(x+12)(x-17)
x = -12 x = 17
We can not have -12 rows but we can have 17 rows.
17 rows is the answer.
