Check the following systems for (i) Linearity (ii) Time invariance (iii) causality (iv) stability
(a)
System
x(t) -> y(t) = t x(t) + t^2 x(t+1)
(b)
System
x(t) -> y(t) = ∫_{-∞}^{0} x(z) dz
Where x(t) and y(t) represent input and output of the System.
Give proper reason for your answer