Let's solve each equation step by step:

1) (2x+3) + (3x+4) + (5x+5) = 12 - 7x

Combine like terms:

2x + 3 + 3x + 4 + 5x + 5 = 12 - 7x
10x + 12 = 12 - 7x
10x + 7x = 12 - 12
17x = 0
x = 0

2) 6x = 1 - (4 - 6x)

Simplify the equation:

6x = 1 - 4 + 6x
6x = -3 + 6x
0 = -3

This equation has no solutions.

3) 6y - (y - 4) = 4 + 5y

Expand and simplify the equation:

6y - y + 4 = 4 + 5y
5y + 4 = 4 + 5y
5y = 5y

This equation is true for all values of y.

4) 5.6 - 7y = -4(2y - 0.9) + 2.4

Expand and simplify the equation:

5.6 - 7y = -8y + 3.6 + 2.4
5.6 - 7y = -8y + 6

Rearrange the equation:

7y - 8y = 6 - 5.6
-y = 0.4
y = -0.4

Therefore, the solutions are:
1) x = 0
2) No solution
3) y is true for all values
4) y = -0.4