Question

The equation of a circle is x^2+y^2+26x-22y+274=0.

What are the center and the radius of the circle?

Answer 1

`(x+5)^(2) +(y+4.7)^(2) = 274`

Explanation:

Put the xs together

`x^(2) +26x + y^(2) -22y+274=0`

move the 274 to the other side, and that will be the
`r^(2)`

`x^(2) +26x + y^(2) -22y=274`

you need
`x^(2)` and
`y^(2)`

so square root 26 is 5.09, so about 5 when rounded

`(x+5)^(2)`

and square root 22 is 4.69, so about 4.7 when rounded

`(y+4.7)^(2)`

so
`x^(2) +26x + y^(2) -22y+274=0`

becomes
`(x+5)^(2) +(y+4.7)^(2) = 274`