Answer:
25
Explanation:
I'm not really sure if this correct its just a guess but here goes.
So as 26x+5 is a vertically opposite angle. So the top angle would be 25x+5.
then we know angles in a triangle add up to 180 degrees so we would add all the angles together. 26x+5+6x-5+20=180. 26x+6x=32x. -5+5=0. 32x+20=180
180-20=160
140/32=5
6×5=30
30-5=25 so angle A is 25?
Please let me know if this is correct and if its not I'm sorry.