If an ordered pair has 0 as it’s x-coordinate, then the point lies on the y-axis

Need this asap if anyone can i would be very grateful. if you could show workings that would really

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

Acircle has a circumference of 28.36 units what is the diameter of the circle