Step-by-step explanation:
the slope of the line is expressed as the ratio
y coordinate change / x coordinate change
when going from one point to the other.
(0, 1) (2, 7)
x changes by +2 (from 0 to 2)
y changes by +6 (from 1 to 7)
the slope is +6/+2 = 6/2 = 3
(4, 5) (1, 1)
x changes by -3 (from 4 to 1)
y changes by -4 (from 5 to 1)
the slope is -4/-3 = 4/3
(1, -2) (4, 7)
x changes by +3 (from 1 to 4)
y changes by +9 (from -2 to 7)
the slope is +3/+9 = 3/9 = 1/3
