Question: (c) $x + y \geq -3$
1. The problem is to understand and graph the inequality $x + y \geq -3$.
2. This inequality represents all points $(x,y)$ in the coordinate plane where the sum of $x$ and $y$ is greater than or equal to $-3$.
3. The boundary line is given by the equation:
$$x + y = -3$$
This line divides the plane into two half-planes.
4. To graph the boundary line, find intercepts:
- When $x=0$, $y = -3$.
- When $y=0$, $x = -3$.
5. Plot points $(0,-3)$ and $(-3,0)$ and draw a straight line through them.
6. Since the inequality is $\geq$, the region above or on the line is included.
7. To check which side to shade, test a point not on the line, for example $(0,0)$:
$$0 + 0 = 0 \geq -3$$ is true, so shade the side containing $(0,0)$.
8. The graph is a half-plane including the line $x + y = -3$ and all points above it.
Final answer: The solution set is the half-plane $x + y \geq -3$ including the boundary line.