Answer:
To subtract the two mixed numbers, we need to convert both mixed numbers to improper fractions.
So,
8/9 = 72/81 (by multiplying both numerator and denominator by 9)
and
4/6 = 40/60 = 2/3 (by multiplying both numerator and denominator by 10/10)
So,
72/81 - 2/3 = (72 * 3 - 2 * 81) / (81 * 3) = (216 - 162) / 243 = 54/243.
So,
8/9 - 4/6 = 54/243.