Can you me with numbers 20-22 a lot of points

We could find the slope with this formula
m = (y₂ - y₁)/(x₂ - x₁)
with (x₁,y₁) and (x₂,y₂) are the points that is located on the line.

NUMBER 20
Given:
(x₁,y₁) = (-2,3)
(x₂,y₂) = (7,-4)

Solution:
Input the points to the formula
m = (y₂ - y₁) / (x₂ - x₁)
m = (-4 - 3) / (7 - (-2))
m = -7 / (7+2)
m = -7/9

The slope of the line is -7/9

NUMBER 21
Given:
(x₁,y₁) = (-6,-1)
(x₂,y₂) = (4,1)

Solution:
Input the points to the formula
m = (y₂ - y₁) / (x₂ - x₁)
m = (1-(-1)) / (4 -(-6))
m = (1+1) / (4+6)
m = 2/10
m = 1/5

The slope of the line is 1/5

NUMBER 22
Given:
(x₁,y₁) = (-9,3)
(x₂,y₂) = (2,1)

Solution:
Input the points to the formula
m = (y₂ - y₁) / (x₂ - x₁)
m = (1 - 3) / (2 - (-9))
m = -2 / (2 + 9)
m = -2/11

The slope of the line is -2/11

How am i goonna know explain