Section 7 test yourself algebra nation answer please

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

We just started the introduction into circles and i have no idea how to do this.

Afamily has five members. a mom, a dad, two sisters, & a brother. the family lines up single file. what is the probabillity that the mom is at the front of the line