Which expression gives the volume of a sphere with radius 7?

If the ratio of sum of the first m and n terms of an ap is m2 : n2 , show that the ratio of its mth and nth terms is (2m − 1) : (2n − 1).

Select the number of ways in which a line and a circle can intersect

Which steps could be part of the process in algebraically solving the system of equations, y+5x=x^2+10 and y=4x-10