[" Find all common langents of "],[" the following pair of circles "],[x^(2)+y^(2)=9" and "x^(2)+y^(2)-16x+2y+49=0]

Find all common tangents of the pairs of circles x^(2) +y^(2) =0 and x^(2) +y^(2) -16x -2y +49=0

Find all common tangents of the pairs of circles x^(2) +y^(2) +4x + 2y -4 =0 and x^(2) +y^(2) -4x -2y +4=0

Find the number of possible common tangents that exist for the following pairs of circles. x^(2) + y^(2) = 4, x^(2) + y^(2) - 6 x - 8y + 16 = 0

The lenght of the common chord of circles x^(2)+y^(2)-6x-16=0 and x^(2)+y^(2)-8y-9=0 is