Anyone? match need it in a rush

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

Aball is dropped from a height of 10m above the ground. it bounce to 90% of its previous height on each bounce. what is the approximate height that the ball bounce to the fourth bounce?

A. use the formula for continuous compounding with the original example: $1000 invested at 2% for 1 year. record the amount to 5 decimal places. use a calculator. b. compare it to the result using the original compound interest formula with n = 365 calculated to 5 decimal places. which has a larger value? explain.