Question

Given f(x) = 6x^2 + 1x + 3 what is the value of f(9)?

Answer 1

f(9)= 6*9^2+1(9)+3
6*81+9+3
486+12
498

Answer 2

We know what the function does with the input so, just replace all x variables with 9.

$f(9) = 6(9)^2 + 1(9) + 3 \\ \\ f(9) = 6(81) + 1(9) + 3 \\ \\ f(9) = 486 + 1(9) + 3 \\ \\ f(9) = 486 + 9 + 3 \\ \\ f(9) = 495 + 3 \\ \\ f(9) = 498$

So, when we input 9 into the function we get 498. f(9) = 498.