4- Solve the following differential equations, if the initial conditions are given use to denitize the arbitrary constants: (5 marks each) a) :-:'+t2y=5t2; y(0) =6 b) 2'2'!'t'+12y+2et=0;y(0)=6 7 C) Solve for both x(t) and y(t) if the two following equations have to be satised simultaneously: 35(1) = 236(1) + 3/0?) r) = "436(1) 3y\")