Triangle perimeter, algebra, systems of equations and inequalities.

Alake near the arctic circle is covered by a sheet of ice during the cold winter months. when spring arrives, the ice starts to melt. s(t) models the ice sheet's thickness (in meters) as a function of time tt (in weeks). s(t)=-0.25t+4

Will mark brainliest question in the pic.

Factor completely. 4p^2 + 36p + 81 express the answer in the form (ap + b)^2