Answer:
Explanation:
Assumptions
You have to make some assumptions here without a diagram, and those assumptions can be wrong.
- The endpoints of <C at the same endpoints as the arc. 
 - The central angle is also 4x
 - The measure of C is 1/2 the measure of the central angle.
 
With these in mind we can go on
Equation
- 2*<C = the measurement of the arc.
 - 2*(x + 5) = 4x Properties of Arcs central angles and interior angles with the vertex and two other points on the legs of angle hitting the circumference.
 
Solution
Remove the brackets
- 2x + 10 = 4x Subtract 2x from both sides
 - 2x - 2x + 10 = 4x - 2x
 - 10 = 2x Divide both sides by 2
 - 10/2 = 2x/2
 - 5 = x Answer