Answer:
The value of x = 12.
Step-by-step explanation:
We know that two angles are termed as supplementary when the sum of the measure of their angles is 180°.
We also know that a straight line angle measures 180°.
It is clear that the angles 72° and 9x° line on a straight line. Thus, the sum of the measure of their angles is 180°.
Therefore,
9x° + 72° = 180°
9x° = 180° - 72°
9x° = 108
divide both sides by 9
9x/9 = 108/9
x = 12
Therefore, the value of x = 12.
