Explanation:
as always when we try to use fractions in a calculation, we convert any mixed fractions into true, proper fractions.
-1 ⅔ is a mixed fraction (a mixture of whole numbers and actual fractions).
the fraction part dictates into what type (denominator) of fraction we want to create. in our case into ⅓.
-1 = -3/3
and minus ⅔ (because the main number is negative, we have to further subtract the fraction part; of the main number is positive, we would have added the fraction part) gives us
-3/3 - 2/3 = -5/3
so, now
(-5/3)² = (-5)²/3² = 25/9