Answer
$(20x+10)^\circ=150^\circ$
$(3x+9)^\circ=30^\circ$
Work Step by Step
The sum of the two angle is a straight angle ($180^\circ$):
$(20x+10)^\circ+(3x+9)^\circ=(23x+19x)^\circ=180^\circ$
$23x+19=180$
$23x=180-19=161$
$x=7$
$(20x+10)^\circ=150^\circ$
$(3x+9)^\circ=30^\circ$