Directions: in each of the following problems, assume a, b, c and d are arbitary constants, determine the equivalent ODE by eliminating the arbitrary constants.

1. y = aex + be3x 2. y = ae2x + be4x 3. x2 + axy + bx + c= 0 4. y = aebx 5. y = a sin (x + b) 6. y = x sin (x + c) 7. y = ae2x + be3x + x2