In Exercises 1-6, find the general solution of the equation specified. 1. dy = -4y +9e- 2. dy = -4y + 3e- dt dt 3. dy = -3y + 4cos 2t 4. dy = 2y + sin 2t dt dt dy 5. dy = 3y - 4e3t 6. - 2 + 4et/2 dt dt 2 In Exercises 7-12, solve the given initial-value problem. 7. dt dy + 2y = et/3, y(0) = 1 g day _ 2y = 3e-21, y(0) = 10 dt o + y = cos 2t, y(0) = 5 10. dy + 3y = cos 2t, y(0) = -1 dt dt 11. dy _ 2y = 7e2, y(0) = 3 12. dy _ 2y = 7e2, y(0) = 3 dt dt