Angelique says that finding the absolute value of a number is the same as finding the opposite of the number. for example |-5|=5. explain her error.

The absolute value takes away the negative sign if there is one. And leaves it alone if there is no negative sign. But if we apply Angelique's way to find an absolute value that would make, say,  |10| = -10. But that is incorrect because all absolute values do is make the positive. Even if it's already positive.