Answer:
x = 20
Explanation:
The sum of the opposite interior angles of a triangle is equal to the exterior angle
x + 2x+10 = 70
Combine like terms
3x+10 = 70
Subtract 10 from each side
3x+10-10 = 70-10
3x = 60
Divide each side by 3
3x/3 = 60/3
x = 20