1. The problem is to solve the equation $x + y = -4$ for one variable in terms of the other. 2. The equation $x + y = -4$ is a linear equation with two variables. To solve for one variable, isolate it on one side of the equation. 3. To solve for $y$, subtract $x$ from both sides: $$y = -4 - x$$ 4. To solve for $x$, subtract $y$ from both sides: $$x = -4 - y$$ 5. These expressions show $y$ in terms of $x$ and $x$ in terms of $y$. Without additional information or another equation, you cannot find unique values for $x$ and $y$. 6. This equation represents a line where any pair $(x,y)$ satisfying $x + y = -4$ is a solution.