What is the sum of 4.2x10^5 and 5.3x10^5

Acircle has a diameter will endpoints of (-2,8) and (6, 4). what is the center of the circle

What is the slope of the equation y =

David estimated he had about 20 fish in his pond. a year later, there were about 1.5 times as many fish. the year after that, the number of fish increased by a factor of 1.5 again. the number of fish is modeled by f(x)=20(1.5)^x. create a question you could ask that could be answered only by graphing or using a logarithm.