What are the prime numbers starting from 1

What number produces an irrational number when multiplied by -1.25

What is the slope simplify your answer and write it as a proper fraction, improper fraction, or integer

The general form of the quetion of a circle is ax^2+by^2+cx+dy+e=0 where a=b=0 if the circle has a radius of three units and the center lies on the y axis which set of values of a, b, c, d, and e might correspond to the circle