Answer
$x=9^\circ$
The two angles are:
$12\times 9^\circ-3^\circ=105^\circ$
$10\times9^\circ+15^\circ=105^\circ$
Work Step by Step
The two given angles are alternate interior angles, which means that they are equal.
$12x-3^\circ=10x+15^\circ$
$2x=18^\circ$
$x=9^\circ$
The two angles are:
$12\times 9^\circ-3^\circ=105^\circ$
$10\times9^\circ+15^\circ=105^\circ$