Answer:
x² + y² - 4x - 10y - 20 = 0
Explanation:
The general equation of circle is
x² + y² + ax + by + c = 0
where a, b and c are constants
To convert the standard form of the equation (x - 2)² + (y - 5)² = 7² into general form, expand the squares and the constant on the right side and adjust the terms to have 0 on the right side
(x - 2)² = x² - 4x + 4
(y - 5)² = y² - 10y + 25
7² = 49
(x - 2)² + (y - 5)² = 7²
= x² - 4x + 4 + y² - 10y + 25 = 49
Subtract 49 from each side to get 0 on the right:
x² - 4x + 4 + y² - 10y + 25 - 49 = 0
Simplify the constant terms
4 + 25 - 49 = 29 - 49 = -20
Required equation is
x² + y² - 4x - 10y - 20 = 0