HELPPPPPPPPPPP PLZZZZZZZZZZZZZZZZZZZZ!!!!!!!!!!!!

Answer:
x = 3
Step-by-step explanation:
The external angle of a triangle is equal to the sum of the 2 opposite interior angles.
10x + 2 is an exterior angle of the triangle, thus
10x + 2 = 2x + 1 + 25
10x + 2 = 2x + 26 ( subtract 2x from both sides )
8x + 2 = 26 ( subtract 2 from both sides )
8x = 24 ( divide both sides by 8 )
x = 3