Arc SCD is two times of angle SED, so arc SCD is 8x+22. Now set 8x+22, 5x-8, and 11x+10 to 360 and solve for x
See the attached picture for the solution:
I believe its letter b. how far from zero because it would determine negative and positive numbers! so wait till an other answer and maybe you will get letter b as the answer hope i helped! <span />
(3x) + (x+60) = 180
4x + 60 = 180
Subtract 60 from both sides
4x = 120
Divide 4 from both sides
x = 30