Answer:
(a) x = 50 , (b) x = 70
Explanation:
(a)
x + 20 and 70 are vertically opposute angles and are congruent (equal), then
x + 20 = 70 ( subtract 20 from both sides )
x = 50
(b)
2x - 50 and x + 20 are vertically opposite angles and are congruent , so
2x - 50 = x + 20 ( subtract x from both sides )
x - 50 = 20 ( add 50 to both sides )
x = 70