Answer:
Option A
Step-by-step explanation:
By using the definition of an exterior angle of a triangle,
"Measure of the exterior angle of a triangle is equal to the sum of measures of the opposite interior angles"
m∠STP = m∠SWT + m∠STW
Substitute the measures of the angles from the picture attached,
15x = (7x + 1) + (7x + 6)
15x = (7x + 7x) + (1 + 6)
15x = 14x + 7
15x - 14x = 7
x = 7
Therefore, Option A will be the correct option.
