Answer:
Step-by-step explanation:
[tex]y(t>1) = x(t) + y(t-1)\\x(t>1) = 1.2x(t-1)\\y(1) = x(1) = 100\\\\y(t>1) = 1.2x(t-1) + y(t-1)\\y(2) = 1.2x(1) + y(1) = 120+100 = 220\\y(3) = 1.2x(2) + y(2) = 144+220 = 364\\y(4) = 1.2x(3) = y(3) = 172.8+364=536.8\\[/tex]