Given the following difference equation with the input-output relationship of a certain initially relaxed system (all initialconditions are zero),
y(n) - 0.7 y(n-1) + 0.1y(n-2) = x(n) + x(n-1)
a. Find the impulse response sequence y(n) due to the impulse sequence δ(n);
b. Find the output response of the system when the unit step function u(n) is applied.