Answer:
x=30
Step-by-step explanation:
The sum of angles of a triangle is 180°, so in ΔRST ...
∠R +∠S +∠T = 180°
(2x+10)° +(2x+25)° +(x-5)° = 180°
5x +30 = 180 . . . . . divide by °, collect terms
5x = 150 . . . . . . . . . subtract 30
x = 30 . . . . . . . . . . . divide by 5
