Acircle's area is equal to its circumference. find the radius of the circle. show work. you!

Kate has 50 quarters and dimes. she has a total of $9.80. how many dimes that she have?

Which is an equation of a circle with center (2, 7) and radius 4? (x - 7)2 + (y - 2)2 = 16 (x - 2)2 + (y - 7)2 = 4 (x – 2)2 + (y - 7)2 = 16 (x + 2)2 + (y + 7)2 = 4

Carmen and matt are conducting different chemistry experiments in school. in both experiments, each student starts with an initial amount of water in a flask. they combine two chemicals which react to produce more water. carmen's experiment starts with 30 milliliters of water in a flask, and the water increases in volume by 8.5 milliliters per second. matt's experiment starts with 10 milliliters of water and increases in volume by 28% each second.