2024年3月C卷练习 · 第 18 题

Circle A in the xy-plane has the equation \( \left(x+9\right)^2+\left(y-9\right)^2=4 \) . Circle B has the same center as circle A. The radius of circle B is two times the radius of circle A. The equation defining circle B in the xy-plane is \( \left(x+9\right)^2+\left(y-9\right)^2=k \) , where k is a constant. What is the value of k?