Question

The following equation describes a circle.

Answer 1

Answer:

Center = (5, -2)  and radius = √33

Step-by-step explanation:

The equation of a circle is given by the formula;

(x-a)² + (y-b)² = r² ; where (a,b) is the center of the circle and r is the radius of the circle.

In this case;

2x² - 20x + 2y² + 8y =40 ;

Dividing both sides of the equation by 2 we get;

x² - 10x + y² + 4y = 20

we can then use the completing the square on both x and y terms.

x² - 10x + y² + 4y = 20

x² + 2(-5)x + 25 + y² + 2(2) y + 4 = 20 +9 + 4

In standard form we get;

(x-5)² + (y+2)² = 33

Therefore;

Center = (5, -2)  and radius = √33