(a-5)^2 + (b-7)^2 = 4 is a circle whose centre is (5,7) and radius is 2
We need to find minimum of (a+7)^2 + (b+2)^2 that is distance of the point A with coordinates a,b fom (-7,-2).
This is minimum when the point lies on the straight line from (-7,2) , (5,7) .
this distane from (-7,2) to (5,7) = \sqrt{(5+7)^2 + (7-2)^2} = 13
the distance of a from (5,7) is 2
so distance of point from (-7,2)is 13 - 2 = 11
so minmum of (a+7)^2 + (b+2)^2 is 121
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