Just plus in x for -3
f(x) = 4(-3)^2 + 3(-3) - 11
f (x) = 4(9) -9 - 11
f(x) = 36 - 20
f(x) = 16
1/3 and 5 because 3/1 is three and 1/3 is the opposite while 1/5 is 5/1 which is 5.
The answer would be 15.7142857143
You can get the answer by calculating (5/7) × 22
12 and 3/8 or if you want it entirely in a fraction 99/8.