To solve the given expression:
(2,4 + 5,8) * 3 целых 5\7

Firstly, we need to perform the addition inside the parentheses:
2,4 + 5,8 = 7,2

Now, the expression becomes:
7,2 * 3 целых 5\7

Next, we need to multiply 7,2 by 3:
7,2 * 3 = 21,6

Therefore, the expression simplifies to:
21,6 целых 5\7

Now, let's simplify the second part of the expression:
(4,9 - 2,3) : 7 \ 9

Perform the subtraction inside the parentheses:
4,9 - 2,3 = 2,6

Now, the expression becomes:
2,6 : 7 \ 9

Next, we need to divide 2,6 by 7:
2,6 / 7 ≈ 0,3714

Therefore, the overall simplified expression is:
21,6 целых 5\7 + 0,3714