Question

Complete the equation of the line through (-8, 8) and (1, -10)

Answer 1

`y=-2x-8`

Explanation:

Let
`y=mx+c` be the equation of this line.

The points must satisfy this equation.

When x=-8, and y=8, we get:

`8=-8m+c....(1)`

When x=1, and y=-10, we get:

`-10=m+c...(2)`

Subtract equation (1) from equation (2) to get:

`m--8m=-10-8`

9m=-18

m=-2

We put m=-2 in equation to get (2)

-10=-2+c

c=-10+2

c=-8

Therefore the equation is:

y=-2x-8