Determine the equation of the straight line through each of the following pairs of data points.

a. (x, y) = (0, 0) and (3, 3)

b. (x, y) = (−1,−5) and (4, 0)

c. (x, y) = (π, 0) and (π²,−π)

d. (x, y) = (−10,−56) and (−100,−129)