Lets consider 2 LTI systems and their impulse response is : $h_1[n]=0.5u[-n-3]$ $h_2[n]=\delta[n-1]-\delta[n]$
The $x[n]=0.5^nu[n]$ signal is applied as the input of the system
The two systems are connected in series
Therefor the equation that should be solved is :$x[n]*(h1[n]*h2[n])$
I am not sure how to solve this because h2 it has the delta function in it
You could use distributive property of convolution to get
$$h_1(n)*h_2(n)=u(n)-u(n-2)$$ Now can you compute the convolution with $x(n)$?