%ex_5
clear all;
x=[1,-2,4,6,-5,8,10];
n=[-2,-1,0,1,2,3,4];
[x1,n1]=sigshift(3*x,n,-2);
[x2,n2]=sigfold(x,n);
[x3,n3]=sigadd(x1,n1,x2,n2);
[y,n]=sigadd(x3,n3,-2*x,n);
stem(n,y),xlabel('n'),ylabel('y'),title('y(n)=3x(n+2)+x(-n)-2x(n)')