Answer:
(x +6)² +(y +3)² = 36
Explanation:
The standard form equation of a circle with center (h, k) and radius r is ...
(x -h)² +(y -k)² = r²
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We have a circle with diameter 12, so its radius is 6. The center is given as (h, k) = (-6, -3), so the equation can be written ...
(x -(-6))² +(y -(-3))² = 6²
Simplifying this a suitable amount, we have the equation ...
(x +6)² +(y +3)² = 36