Determine which of the following linear systems is causal. baan dent input 3.8: bounded output a. y(n) = 0.5 x(n) + 100x(n-2)- 20x(n-10) b. y(n) = x(n+4)+ 0.5 x(n) - 2x(n-2) 3.9: b. y(n) = x(n + 2) - 0.4y(n - 1) c. y(n) = x(n-1) + 0.5 y(n + 2) == L g(+) يحمد على زمن