Why when I ask a question the right answers aren't given or another problem comes up

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

You got a job selling magazines door-to-door. you are paid $100 per day plus $1.50 for each magazine you sell. which recursive formula models this situation?

Solve for x and y: 217x + 131y = 913; 131x + 217y = 827