1. **State the problem:** We need to graph the inequality $3x + 4y \geq 12$ on the Cartesian plane.
2. **Rewrite the inequality as an equation to find the boundary line:**
$$3x + 4y = 12$$
This line divides the plane into two regions.
3. **Find the intercepts of the boundary line:**
- For the $x$-intercept, set $y=0$:
$$3x + 4(0) = 12 \implies 3x = 12 \implies x = 4$$
- For the $y$-intercept, set $x=0$:
$$3(0) + 4y = 12 \implies 4y = 12 \implies y = 3$$
4. **Plot the boundary line:**
The line passes through points $(4,0)$ and $(0,3)$.
5. **Determine which side of the line to shade:**
Choose a test point not on the line, for example $(0,0)$.
Substitute into the inequality:
$$3(0) + 4(0) = 0 \geq 12$$
This is false, so the region containing $(0,0)$ is NOT part of the solution.
6. **Shade the opposite side:**
Shade the region on the side of the line opposite to $(0,0)$, which satisfies $3x + 4y \geq 12$.
7. **Include the boundary line:**
Since the inequality is $\geq$, the boundary line itself is included (solid line).
Final answer: The graph is the line through $(4,0)$ and $(0,3)$ with the region above (or to the side opposite $(0,0)$) shaded, including the line itself.
Graph Inequality 70380B
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