The table shows the soil density of several soil samples at different depths. (a) Write the quadratic regression equation that models the data. Let x = depth below the surface and let y = soil density. (b) Use the equation to estimate the soil density of a sample at a depth of 20 m. Show your work.

Use set buikder notation to represent the following set: {, -2, -1, 0}

Acircle has a circumference of 7.850 units. what is its radius?

Every weekday, mr. jones bikes from his home to his job. sometimes he rides along two roads, the long route that is shown by the solid lines. other times, he takes the shortcut shown by the dashed line. how many fewer kilometers does mr. jones bike when he takes the shortcut instead of the long route?