SOLUTION: x^2+y^2+8x+2y+13=0 Find the center and radius. If someone could explain the steps that would be great!!

Question 262418: x^2+y^2+8x+2y+13=0 Find the center and radius. If someone could explain the steps that would be great!!
Answer by drk(1908) (Show Source): You can put this solution on YOUR website!
Here is the original equation
(i)
step 1 - rearrange the terms so that x's are grouped and y's are grouped together.
(ii)
the blanks are waiting for certain numbers
step 2 - take 1/2 of the middle terms and square it
(1/2)*8 = 4 -> 4^2 = 16
(1/2)*2 = 1 -> 1^2 = 1
so, we get
(iii)
notice that the blanks were filled in with the squared numbers.
step 3 - rewrite the x any y trinomial as a binomial squared. Also, simplify the right side to get
(iv)
notice that the constant is 1/2 the middle term.
we have everything we need to find center and radius.
center = (h,k) = (-4,-1)
radius = 2
RELATED QUESTIONS
Hi everyone, I would like some help with the following question. I need to solve the... (answered by jim_thompson5910)

Hi all, I was wondering if someone could help with the following: I need to determine... (answered by Alan3354)

find the center and radius of a circle... (answered by lynnlo)

Show steps please. A circle has the equation x^2+y^2-x-4y+4=0 Graph the circle using... (answered by Alan3354)

Find the center and radius of the circle given by the equation x^2 + y^2 - 8x + 2y - 11 = (answered by nerdybill)

For the circle with equation (x � 2)^2 + (y + 3)^2 = 9, answer each question: What are... (answered by MathLover1,stanbon)

"Use The Info Provided To Write The Standard Form Equation Of Each Circle" {{{... (answered by Boreal,Alan3354)

Find the Center and radius of the circle whose equation is: x^2+8x+y^2+1y-2=0 I... (answered by Fombitz)

Write the equation of the circle in standard form.��Find the center, radius, intercepts,... (answered by lwsshak3)