To solve the equation \( 15 - 11y = -7y + 12 - 4y \), let's simplify both sides.
First, simplify the right side:
\[ -7y + 12 - 4y = -11y + 12 \]
Now, the equation can be rewritten as:
\[ 15 - 11y = -11y + 12 \]
Next, let's add \( 11y \) to both sides:
\[ 15 = 12 \]
This statement \( 15 = 12 \) is clearly false. Since we reached a contradiction that indicates the left side and right side cannot be equal for any value of \( y \), we conclude that there are no solutions to the equation.
Thus, the final answer is:
\[ \text{The equation has no solutions.} \]