The first step is to subtract the fractions inside the parenthesis.
3 2/3 - 2 1/3 = 1

Now we have:
(2,75:1,75) × 3 2/21 =

Next, we need to convert the mixed numbers to improper fractions.
2,75 = 11/4
1,75 = 7/4

Now we have:
(11/4 ÷ 7/4) × 3 2/21 =

Dividing the fractions:
(11/4 ÷ 7/4) = 11/4 ÷ 7/4 = 11/4 × 4/7 = 11/7

Now we have:
(11/7) × 3 2/21 =

Multiplying the fractions:
(11/7) × (3 2/21) = (11/7) × (65/21) = 715/147 = 55/3

Therefore, (2,75:1,75) × 3 2/21 = 55/3