The graph of the equation y = mx + c passes through the points (1, 4) and (-2, -5). Determine the values of m and c.

Find the equation of the line passing through the point (2, -5) and making an intercept of -3 on the y-axis.

Find the equation of a straight line whose inclination is 60° and which passes through the point (0, -3).

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

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

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