Find the gradient of a line passing through the following pairs of points :

(i) (0, -2), (3, 4)

(ii) (3, -7), (-1, 8).

Find the value of 'a' for which the following points A(a, 3), B(2, 1) and C(5, a) are collinear. Hence, find the equation of the line.

Find the equation of the line passing through the points P(5, 1) and Q(1, -1). Hence, show that the points P, Q and R(11, 4) are collinear.

The coordinates of two points E and F are (0, 4) and (3, 7) respectively. Find :

(i) the gradient of EF.

(ii) the equation of EF.

(iii) the coordinates of the point where the line EF intersects the x-axis.