Answer:
x = 4
Step-by-step explanation:
The exterior angle of a triangle is equal to the sum of the 2 opposite interior angles.
(19x + 3)° is an exterior angle of the triangle, then
11x - 2 + 9x + 1 = 19x + 3
20x - 1 = 19x + 3 ( subtract 19x from both sides )
x - 1 = 3 ( add 1 to both sides )
x = 4
