a
$\left|\begin{array}{lll}{e^{\alpha}} & {e^{2 \alpha}} & {e^{3 \alpha+1}} \\ {e^{\beta}} & {e^{2 \beta}} & {e^{3 \beta+1}} \\ {e^{\gamma}} & {e^{2 \gamma}} & {e^{3 \gamma+1}}\end{array}\right|-\left|\begin{array}{ccc}{e^{\alpha}} & {e^{2 \alpha}} & {e^{-\delta}} \\ {e^{\beta}} & {e^{2 \beta}} & {e^{-\delta}} \\ {e^{\gamma}} & {e^{2 \gamma}} & {e^{-\delta}}\end{array}\right|$
$e^{\alpha} \cdot e^{\beta} \cdot e^{\gamma} \cdot e^{1}\left|\begin{array}{ccc}{1} & {e^{\alpha}} & {e^{2 \alpha}} \\ {1} & {e^{\beta}} & {e^{2 \beta}} \\ {1} & {e^{\gamma}} & {e^{2 \gamma}}\end{array}\right|-e^{-\delta}\left|\begin{array}{ccc}{1} & {e^{\alpha}} & {e^{2 \alpha}} \\ {1} & {e^{\beta}} & {e^{2 \beta}} \\ {1} & {e^{\gamma}} & {e^{2 \gamma}}\end{array}\right|$
$\left(e^{\alpha+\beta+\gamma+1}-e^{-\delta}\right)\left|\begin{array}{ccc}{1} & {e^{\alpha}} & {e^{2 \alpha}} \\ {1} & {e^{\beta}} & {2^{2 \beta}} \\ {1} & {e^{\gamma}} & {e^{2 \gamma}}\end{array}\right|=0$
$\because \alpha+\beta+\gamma+\delta+1=0$