2.2.1.6 ✓ Mathematica. Time used: 0.03 (sec). Leaf size: 18

ode=D[x[t],t]==\[Lambda]*x[t]; 
ic={}; 
DSolve[{ode,ic},x[t],t,IncludeSingularSolutions->True]
 

\begin{align*} x(t)&\to c_1 e^{\lambda t}\\ x(t)&\to 0 \end{align*}