Answer:
x = 25
Explanation:
The top angle is the supplement of 3x - 10
180 - (3x - 10) = -3x + 190
The sum of the angles in a triangle is 180
(-3x + 190) + (25) + (x + 15) = 180
Combine like terms
-2x + 230 = 180
Subtract 230 from both sides
-2x = -50
Divide both sides by -2
x = 25