Answer:
x=3
Step-by-step explanation:
The exterior angle of a triangle is equal to the sum of the opposite interior angles
45x = 25x+57+x
Combine like terms
45x = 26x+57
Subtract 26x from each side
45x-26x = 26x+57-26x
19x = 57
Divide by 19
19x/19 = 57/19
x = 3
