The distance that an object falls when dropped

Idon’t understand this.. will someone ? will mark brainliest along with 20 points.

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

Someone answer asap for ! the following statements are true about the coins calvin and sasha have collected. * calvin and sasha has the same amount of money. * calvin has only quarters. * sasha has dimes, nickels, and pennies * calvin has the same number of quarters as sasha has dimes. * sasha has $1.95 in coins that are not dimes. exactly how many quarters does calvin have?