What is the ratio of the radius of a circle to its circumference?

a) 1/2pi
b) (1/pi)r
c) 1/pi

Can someone explain to me how to do

Agrid shows the positions of a subway stop and your house. the subway stop is located at (-5,2) and your house is located at (-9,9). what is the distance, to the nearest unit, between your house and the subway stop?

28 x 12 + 34 = ? it's for a test that if i fail on i will not proceed into the honor roll society i always dreamed of!me! worth 50 !