A flower-bed can be schematicly represented as two concentric circles with two different flowers in the inner circle area and outer ring area as shown in the figure below. The boundary of the inner flower-bed can be described by the following equation:
x 2 - 4y + 6x + y^2 = 6.75
where all measurements are given in metres. The radius of the outermost ring is 1.5 m greater than the radius of the inner circle. Find the equation that represents the outermost boundary of the flower-bed and indicate coordinates of its centre and radius.