Consider the following pairs of points:
P(−3,4),Q(5,−2);
R(7,5),S(7,−3);
U(2,6),V(−4,6).
(i) For each pair of points, calculate the slope of the line segment joining them and write the value in simplest form.
(ii) State, with reason, whether each of the three line segments is inclined upward, inclined downward, horizontal, or vertical when observed from left to right along the x–axis.
(iii) Arrange the three obtained slopes in ascending order wherever meaningful, explaining any case where an arrangement is not possible.