Answer:
45
Step-by-step explanation:
The sum of interior angles in a triangle is equal to 180
2x - 12 + 2x + 17 + 9x - 7 = 180 add like terms
13x - 2 = 180 add 2 to both sides
13x = 182 divide both side by 13
x = 14
m<X = 2x + 17 replace x with 14
2*14 + 17 = 45
