Calculate impulse response for given system i am given an exercise in which i need to find the impulse response for this given system: $$y(n) = 2x(n-2) + x(n) -2x(n+2)$$ This is the only information i have. I don't even understand which formula should be applied to get the result. May any merciful soul help me on my way to find the solution? :) Thanks!

You only need to apply an impulse input (i.e. $x(n) = \delta (n)$), and see what is the response $y(n)$ (It is usually called $h(n)$). In this case, as the output does not depend on its self, you simply obtain: $$h(n) = \delta (n) + 2 \delta (n-2) - 2 \delta (n+2) $$ From this impulse response you can obtain the response for any input.