Answer:
x = 13
Step-by-step explanation:
Sum or interior angles of a triangle is 180,
6x + 19 + 5x - 15 + 3x - 6 = 180
6x + 5x + 3x + 19 - 15 - 6 = 180
14x + 19 - 21 = 180
14x - 2 = 180
14x = 180 + 2
14x = 182
x = 182 / 14
