Question

Find the equation of the line through (-8,-7) and (0,-9)

Answer 1

If the equation of the line is linear function, then the solution consist of theese steps:
1. equation of line y=kx+b, where k and b - numbers, x and y coordinates of points.
2. using the equation of the line it is possible to substitute coordinates of points into equation:

`\left \{ {{-7=-8*k+b} \atop {-9=0*k+b}} \right. \ =\ \textgreater \ \ \left \{ {{-8k+b=-7} \atop {b=-9}} \right. \ =\ \textgreater \ \ \left \{ {{k=- (1)/(4)} \atop {b=-9}} \right.`
3. the equation is:

`y=- (1)/(4)x-9`

Answer 2

What is the formula for this equation?