Graph System
1. Stating the problem: We need to graph the system of equations:
$$x+2y=6$$
$$x-y=-6$$
2. Solve each equation for $y$ to express in slope-intercept form $y=mx+b$:
From the first equation:
$$x+2y=6 \\ 2y=6 - x \\ y=\frac{6 - x}{2} = 3 - \frac{x}{2}$$
From the second equation:
$$x - y = -6 \\ -y = -6 - x \\ y = x + 6$$
3. The two lines to graph are:
$$y = 3 - \frac{1}{2}x$$
$$y = x + 6$$
4. (Optional) Find the intersection point by solving the system:
Set the right sides equal:
$$3 - \frac{x}{2} = x + 6$$
Multiply both sides by 2 to clear fraction:
$$6 - x = 2x + 12$$
Bring variables to one side:
$$6 - x - 2x = 12 \\ 6 - 3x = 12$$
Subtract 6:
$$-3x = 6$$
Divide by -3:
$$x = -2$$
Substitute back to find $y$:
$$y = x + 6 = -2 + 6 = 4$$
Hence, the two lines intersect at point $(-2, 4)$.
5. Conclusion: To graph, plot the two lines:
- Line 1: slope $-\frac{1}{2}$, y-intercept 3.
- Line 2: slope 1, y-intercept 6.
They intersect at $(-2, 4)$.