Since this is an equilateral triangle, TV=VX. You can set TV equal to VX to solve for the value of x. The expression would be 10x-26=5x+9. Subtract 5x from both sides to get 5x-26=9. Add 26 to both sides to get 5x=35. Lastly, divide by 5 to get x=7.
So, your answer would be 7 degrees. Hope this helps!