Răspuns:
f(x)=4
f(1)=4-1=3
f(2)=4-2=2
f(3)=4-5=‐1
f(x) = 4 - x
f(1) = 4 - 1 = 3 =>f(1)=3
f(3) = 4 - 3 = 1=>f(3) = 1
f(5) = 4-5 = - 1 =>f(5) = - 1