Answer:
(x-5)² +(y-1)² = 0 . . . . the last selection
Step-by-step explanation:
A "degenerate" anything generally has some dimension that is zero. A degenerate circle is a circle of radius 0, a point. The last selection is the equation of a circle centered at (5, 1) with radius zero. That is your degenerate circle.
B: 9/16
7 777777777777777777777777777777777
15m+20
5(3m+4)
5*3m, 5*4