Question

y = x + 8\
2x + y = -7\
plot two lines by clicking the graph.\
click a line to delete it.

Explanation:

Step1: Find points for $y=x+8$

When $x=0$, $y=0+8=8$; when $x=-8$, $y=-8+8=0$. So points are $(0,8)$ and $(-8,0)$.

Step2: Rewrite second equation

Rearrange $2x+y=-7$ to $y=-2x-7$.

Step3: Find points for $y=-2x-7$

When $x=0$, $y=-2(0)-7=-7$; when $x=-\frac{7}{2}$, $y=-2(-\frac{7}{2})-7=0$. So points are $(0,-7)$ and $(-3.5,0)$.

Step4: Find intersection (solve system)

Substitute $y=x+8$ into $2x+y=-7$:
$2x+(x+8)=-7$
$3x+8=-7$
$3x=-15$
$x=-5$
Then $y=-5+8=3$. Intersection is $(-5,3)$.

Answer:

1. For $y=x+8$: Plot and connect points $(0,8)$ and $(-8,0)$.
2. For $2x+y=-7$ (or $y=-2x-7$): Plot and connect points $(0,-7)$ and $(-3.5,0)$.
3. The lines intersect at $(-5,3)$.