What is the rate of change in miles ran from September 6th to September 15th?

In the figure dhg fhe which statement is true by cpctc

The lengths of two sides of a right triangle are given. find the length of the third side. round to the nearest tenth if necessary. a) y = 12/5x + 39/5 b) y = 5/12x + 5/39 c) y = 12/5x - 39/5 d) y = 5/12x - 5/39

How do i i solve this equation? -18 = x/3 + 3