Răspuns :
f(-2)=2*(-2)-1=-4-1=-5
f(-1)=2*(-1)-1=-2-1=-3
f(0)=2*0-1=0-1=-1
f(1)= 2*1-1=2-1=1
-5+(-3)+(-1)+1=-5-3-1+1=si faci calculul
f(-1)=2*(-1)-1=-2-1=-3
f(0)=2*0-1=0-1=-1
f(1)= 2*1-1=2-1=1
-5+(-3)+(-1)+1=-5-3-1+1=si faci calculul