Answer:
x = 12
Explanation:
If line r and line a are parallel, therefore:
(11x - 28) + (7x - 8) = 180° (consecutive interior angles are supplementary)
Solve for x
11x - 28 + 7x - 8 = 180
Add like terms
18x - 36 = 180
18x = 180 + 36 (addition property of equality)
18x = 216
x = 216/18 (division property of equality)
x = 12