# Math Help - graphing a cricle

1. ## graphing a cricle

x^2+10x+y^2-10y+46=0

how do you put that in standard form for a circle?

2. Originally Posted by danimals24
x^2+10x+y^2-10y+46=0

how do you put that in standard form for a circle?
Equation of a circle with centre (a,b) and radius r: $(x-a)^2 + (y-b)^2 = r^2$

Complete the square for x and y:

$(x+5)^2 = x^2+10x {\color{red} +25} \rightarrow x^2+10x = (x+5)^2 {\color{red} -25}$.

You can do the same with y to give $y^2-10y = (y-5)^2 {\color{red} -25}$

Once you've done that collect the constants together and move them over to the right hand side.