Answer:
x=9
Step-by-step explanation:
Use the intersecting chord theorem:
RE*ET = UE*ES
Substitute values
21 (2x+2) = 30 (x+5)
Expand:
42x+42 = 30x + 150
transpose and simplify
42x-30x = 150 - 42
12x = 108
x = 9
