Identify the center and radius from the equation of the circle given below. x^2+y^2+121-20y=-10x

Center: (-5,10)

Radius: 2

Step-by-step explanation:

The equation of the circle in center-radius form is:

Where the point (h,k)  is the center of the circle and "r" is the radius.

Subtract 121 from both sides of the equation:

Add 10x to both sides:

Make two groups for variable "x" and variable "y":

Complete the square:

Add inside the parentheses of "x".

Add    inside the parentheses of "y".

Add and to the right side of the equation.

Then:

Rewriting, you get that the equation of the circle in center-radius form is:

You can observe that the radius of the circle is:

And the center is:

step-by-step explanation: a reaction is first order. if the initial reactant concentration is 0.0200 m, and 25.0 days later the concentration is 6.25 x 10-4 m, then its half-life is:

what are the options? ?

step-by-step explanation: