Part A: Understanding System’s Properties
Definition of a Memoryless System - A system is said to be memoryless if for any $ t \in \mathbb{R} \! $ the output $ y(t)\! $ depends only on the input at $ t\! $ (as opposed to $ (t-t_0)\! $,$ (-t)\! $, etc).
Definition of a System with Memory - A system is said to have memory if for any $ t \in \mathbb{R} \! $ the output $ y(t)\! $ depends on either a past or future value of $ t\! $, such as $ (t+t_0)\! $.