Answer:
x=35
Explanation:
These are alternate interior angles. Since a and b are parallel, they are equal
5x - 54 = 3x+16
Subtract 3x from each side
5x-3x -54 = 3x -3x +16
2x -54 = 16
Add 54 to each side
2x-54+54 = 16+54
2x = 70
Divide each side by 2
2x/2 = 70/2
x = 35