Question:
What is the shortest distance, in units, between the circles $(x-9)^2 + (y-5)^2 = 6.25$ and $(x+6)^2 + (y+3)^2 = 49$? Express your answer as a decimal to the nearest tenth.

Answer:
The first circle is centered at $(9,5)$ and has a radius of $\sqrt{6.25} = 2.5$. The second circle is centered at $(-6,-3)$ and has a radius of $\sqrt{49} = 7$. To find the shortest distance between the circles, we draw a segment connecting their centers, and subtract off the radii of the two circles. The distance between the centers of the circles is $\sqrt{(9-(-6))^2 + (5-(-3))^2} = \sqrt{15^2+8^2} = 17$. So the shortest distance between the circles is $17 - 2.5 - 7 = \boxed{7.5}$.