6x + 12 - x - x + 8 = 2x + 10 + 2x + 10
6x + 12 - x - x + 8 = 6x - x - x + 12 + 8 = 4x + 20
2x + 10 + 2x + 10 = 2x + 2x + 10 + 10 = 4x + 20
Both expressions are equivalent for all the values of x, because they are equal when simplified.
Answer:
They are equivalent for all the values of x