The general form of the equation of a circle is x2+y2−8x+6y+21=0. What are the coordinates of the center of the circle?

Samantha swam upstream for some distance in one hour. she then swam downstream the same river for the same distance in only 12 minutes. if the river flows at 4 mph, how fast can samantha swim in still water?

Regular price 75$ discount 25%sale price?

Marla bought a book for $12.95, a binder for $3.49, and a backpack for $44.99. the sales tax rate is 6%. find the amount of tax and the total she paid for these items