Question

What is the equation for this?

Answer 1

The point-slope form:

`y-y_1=m(x-x_1)\\\\m=(y_2-y_1)/(x_2-x_1)`

We have two points (-9, 7) and (9, 1). Substitute:

`m=(1-7)/(9-(-9))=(-6)/(18)=-(1)/(3)\\\\y-7=-(1)/(3)(x-(-9))\\\\\boxed{y-7=-(1)/(3)(x+9)}`