I dont understand this LTI system, what will be the output of y(t)​

Evaluate 4 a for a = 5 2/3 . express your answer in simplest form.

Abox contains 1 plain pencil and 4 pens. a second box contains 5 color pencils and 5 crayons. one item from each box is chosen at random. what is the probability that a plain pencil from the first box and a color pencil from the second box are selected? write your answer as a fraction in simplest form.

What is the y-intercept of the line given by the equation