Answer:
x = 25
Step-by-step explanation:
Make use of the fact that the sum of angle measures in a triangle is 180°.
(2x+15)° +(3x+5)° +(x+10)° = 180°
6x +30 = 180 . . . collect terms, divide by °
x +5 = 30 . . . . . . divide by 6
x = 25 . . . . . . . . . subtract 5
_____
Check
This value of x makes the angle measures be ...
A = (x+10)° = 35°
B = (3x+5)° = 80°
C = (2x+15)° = 65°
These angles total 180°.
