No links and answer this if you have an explanation for the answer you got plz :)

Find the center and the radius of the circle with the equation: x^2-2x+y^2+4y+1=0?

Cody started biking to the park traveling 15 mph, after some time the bike got a flat so cody walked the rest of the way, traveling 4 mph. if the total trip to the park took 6 hours and it was 46 miles away, how long did cody travel at each speed? solve using rate times time= distance

Jan accidently ran 7 minutes longer than he was supposed to. write an expression for the total amount of time jan ran if she was supposed to run m minutes