To analyze electric circuits, it is often necessary to solve simultaneous equations. To find the voltages Va, Vb, and Vc at nodes a, b, and c, the equations are
2(Va-Vb) + 5(Va-Vc) - e^(-t) =0
2(Vb-Vc) + 2Vb + 3(Vb-Vc) =0
Vc = 2sin(t)
Find out how to use the solve function to solve for Va, Vb, and Vc so that the solution will be returned in terms of t.