If a particular integral of the differential equation \((D^2+2D-1)y=e^{ax}\) is \(\frac{{ - 4}}{7}{e^{ax}}\), then the value of 'a' is
1
\(\left( {\frac{1}{2}~or~\frac{3}{2}} \right)\)
2
\(\left( {\frac{{ - 1}}{2}~or~\frac{{ - 3}}{2}} \right)\)
3
\(\left( {\frac{1}{2}~or~\frac{{ - 3}}{2}} \right)\)
4
\(\left( {\frac{{ - 1}}{2}~or~\frac{3}{2}} \right)\)