If roots of the auxiliary equation of $$\frac{{{{\text{d}}^2}{\text{y}}}}{{{\text{d}}{{\text{x}}^2}}} + {\text{a}}\frac{{{\text{dy}}}}{{{\text{dx}}}} + {\text{by}} = 0$$     are real and equal, the general solution of the differential equation is

Correct Answer: $${\text{y}} = \left( {{{\text{c}}_1} + {{\text{c}}_2}{\text{x}}} \right){{\text{e}}^{ - \frac{{{\text{ax}}}}{2}}}$$