Hey guys im kinda new in matlab and im trying to calculate the convolution of these 2 signals:
          h(k)=0.7k,0?k?10 ??? x(k)=u(k)-u(k-4). i would apreciate some help:)
thanks!!

I don't understand the syntax.  What's with all those question marks?  Did you try

out = conv(h,x);

???