Need the answer find the slope of the line that passes through each pair of points

Y2-y1/x2-x1
3-0/-1-0
3/-1

The slope of the line is:  -3 .

Explanation:

Use the slope formula:

The slope, "m",  of a line with the 2 (TWO) points:

            (x₁, y₁) and (x₂, y₂) ;


 m = (y₂ - y₁) / (x₂ - x₁);  if x₁  ≠ x₂ ;  and:  "m" is undefined if  x₁ = x₂ .

So we are given the points:  (0, 0), and (-1, 3) ;

   in which , x₁ = 0 ;  y₁ = 0 ;   x₂ = -1;   y₂ = 3 ;

The slope, "m":

    m = (y₂ - y₁) / (x₂ - x₁) = (3 - 0) / (-1 - 0) = 3 / -1 = -3 .

The slope of the line is:  -3 .