What is the square root of 345,920,879?

Bring the fraction a/a-4 to a denominator of 16-a^2

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?

The perimeter of a quarter circle is 14.28 miles. what is the quarter circle's radius?