Answer:
x = 10
Explanation:
The internal angles of a triangle sum 180°
74° + 45°+ (8x-19)° = 180°
119 + 8x - 19 = 180
119 - 19 + 8x = 180
100 + 8x = 180
8x = 180 - 100
8x = 80
x = 80/8
x = 10
Check:
74 + 45 + (8x-19) = 180
1100 + 8*10 = 180
100 + 80 = 180