Use the quadratic function to predict f(x) if x equals 8. f(x) = 25x2 − 28x + 585 f(8) = 2679 f(8) = 1614 f(8) = 1961 f(8) = 2201

To predict f(x) when x equals 8 we simply substitute.
 So f(x) = 25x2 28x + 585
  f(8) = 25 (8)^2 - 28 (8) + 585
  f(8) = 25 * 64 - 224 + 585
  f(8) = 1600 - 224 + 585 = 1961
  Hencse f(8) = 1961

I’m not absolutely sure but i think it’s 7x6x5x4x3x2=5040 because as the first character you can take any of the 7 given then you are left with 5 then 6 then 4 etc.