9514 1404 393
 ∠S = 38°
Step-by-step explanation:
The sum of angles in a triangle is 180°, so you have ...
 (x+17)° +(2x-2)° +(5x+5)° = 180°
 8x +20 = 180  . . . . .  divide by °, collect terms
 8x = 160 . . . . subtract 20
 x = 20 . . . . . . divide by 8
∠S = (2x -2)° = (2·20 -2)°
∠S = 38°