Bluebook试题6 · 第 22 题

Bluebook试题6 · 原库模块 1 · Q22 原库参考解析

Circle A (shown) is defined by the equation \( \left(x+2\right)^2+y^2=9 \) . Circle B (not shown) is the result of shifting circle A down 6 units and increasing the radius so that the radius of circle B is 2 times the radius of circle A. Which equation defines circle B?