Help please! very important

Look at the following graph of the given equation. determine whether the equation is a function. explain why or why not.

Sorry guys but as you have a small brain

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