If y1 is a solution of y''' + p1(t)y'' + p2(t)y' + p3(t)y = 0, then the substitution y = y1(t)v(t) leads to the following second order equation for v': y1v''' + (3y1' + p1y1)v'' + (3y1'' + 2p1y1' + p2y1)v' = 0. Use the method of reduction of order above to solve the given differential equation. (2 − t)y''' + (2t − 3)y'' − ty' + y = 0, t < 2; y1(t) = et