Question

If the radius of the circle $x ^ { 2 } + y ^ { 2 }$ $- 18 x + 12 y + k = 0$ be 11, then $k =$

• A. 347
• B. 4
• C. $- 4$
• D. 49

Answer 1

Answer: (C)

$- 4$

Answer 2

or $121 = 81 + 36 - k$ or $k = - 4$.