Trigonometry
x = t/3 and y = 3t - 5; x = t/9 and y = t - 5
x = 3t and y = 3t - 5; x = 9t and y = t - 5
x = 9t and y = 3t - 5; x = t and y = t - 5
x = 9t - 5 and y = 3t - 5; x = 9/t and y = t - 5