1. **State the problem:** We are given the system of equations:
$$9x + y = 28$$
$$x + y = -4$$
and a table of points to verify, plus we need to find the slope of the line.
2. **Find the solution for $x$ and $y$:**
From the second equation, isolate $y$:
$$y = -4 - x$$
Substitute into the first equation:
$$9x + (-4 - x) = 28$$
Simplify:
$$9x - 4 - x = 28$$
$$8x - 4 = 28$$
Add 4 to both sides:
$$8x - \cancel{4} + \cancel{4} = 28 + 4$$
$$8x = 32$$
Divide both sides by 8:
$$\frac{8x}{\cancel{8}} = \frac{32}{\cancel{8}}$$
$$x = 4$$
Substitute $x=4$ back into $y = -4 - x$:
$$y = -4 - 4 = -8$$
So the solution is:
$$X = (4, -8)$$
3. **Verify the points in the table:**
- For $x = -2$, $y = 9$
- For $x = 8$, $y = 11$
- For $x = 13$, $y = 12$
Check if these satisfy the first equation $9x + y = 28$:
- $9(-2) + 9 = -18 + 9 = -9 \neq 28$
- $9(8) + 11 = 72 + 11 = 83 \neq 28$
- $9(13) + 12 = 117 + 12 = 129 \neq 28$
They do not satisfy the first equation, so these points are not on the line defined by the system.
4. **Find the slope of the line:**
Rewrite the second equation as $y = -4 - x$ which is $y = -x - 4$.
The slope-intercept form is $y = mx + b$, so the slope $m = -1$.
**Final answers:**
$$X = (4, -8)$$
Slope: $$-1$$
Solve System 524D6F
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