Answer
$t=\frac{14}{9}$
Work Step by Step
Using the fact that $\sqrt{a}=a^\frac{1}{2}$ and $(a^m)^n=a^{mn}$, the equation becomes $$e^\frac{9t}{2}=e^7$$ This implies that $\frac{9t}{2}=7$. Multiply both sides by $\frac{2}{9}$ to cancel the fractional coefficients and get $$t=7 \cdot \frac{2}{9}=\frac{14}{9}$$