Linear Inequalities Region E61676
1. **Problem Statement:** We need to find and indicate the solution region for the system of linear inequalities:
$$3x + 7y \leq 21$$
$$x - y \geq 2$$
2. **Understanding the inequalities:**
- The first inequality, $3x + 7y \leq 21$, represents all points $(x,y)$ on or below the line $3x + 7y = 21$.
- The second inequality, $x - y \geq 2$, represents all points $(x,y)$ on or above the line $x - y = 2$.
3. **Rewrite the boundary lines in slope-intercept form:**
- For $3x + 7y = 21$:
$$7y = 21 - 3x$$
$$y = \frac{21 - 3x}{7} = 3 - \frac{3}{7}x$$
- For $x - y = 2$:
$$-y = 2 - x$$
$$y = x - 2$$
4. **Determine the solution regions for each inequality:**
- For $3x + 7y \leq 21$, the region is below or on the line $y = 3 - \frac{3}{7}x$.
- For $x - y \geq 2$, the region is above or on the line $y = x - 2$.
5. **Find the intersection points of the boundary lines to understand the feasible region:**
Set
$$3 - \frac{3}{7}x = x - 2$$
Multiply both sides by 7:
$$21 - 3x = 7x - 14$$
Bring all terms to one side:
$$21 + 14 = 7x + 3x$$
$$35 = 10x$$
$$x = 3.5$$
Substitute back to find $y$:
$$y = 3.5 - 2 = 1.5$$
6. **Interpretation:**
The solution region is the intersection of the half-planes below the first line and above the second line. This region lies between the two lines and includes the point $(3.5, 1.5)$ where they intersect.
7. **Summary:**
- Shade the area below or on $y = 3 - \frac{3}{7}x$.
- Shade the area above or on $y = x - 2$.
- The solution region is where these shaded areas overlap, which is the region between the two lines including their boundaries.
**Final answer:** The solution region is the set of points satisfying both $3x + 7y \leq 21$ and $x - y \geq 2$, i.e., the area between and including the lines $y = 3 - \frac{3}{7}x$ and $y = x - 2$.