Transform the given system into a single equation of second$-$order

$x_1^{\text{'}}=31x_1-30x_2$

$x_2^{\text{'}}=30x_1-30x_2.$

Then find $x_1$ and $x_2$ that also satisfy the initial conditions

$x_1(0)=9$

$x_2(0)=3.$

NOTE: Enter exact answers.

$x_1(t)=$

$$

$x_2(t)=$

$$