help with circles

[dapper cliff]

On 21 what are the steps to solve

[lost cloak]

What the task

[night yacht]

So I'm guessing it's asking you for the centre of the circle/radius of the circle. If so, you want to complete the square twice, once for the x and once for the y to make it into the form of (x-x_1)^2 + (y-y_1)^2 = r^2.

,tex $(x-x_1)^2 + (y-y_1)^2 = r^2$

[kindred lichen]

AsianFailure

[night yacht]

So here's are the exact workings

,tex $16x^2 + 16y^2 + 8x - 32y = 127$

[kindred lichen]

AsianFailure

[night yacht]

,tex $16(x^2 + (1/2)x) + 16(y^2 - 2y) = 127$

[kindred lichen]

AsianFailure

[night yacht]

,tex $(x^2 + (1/2)x) + (y^2 - 2y) = 127/16$

[kindred lichen]

AsianFailure

[night yacht]

,tex $(x + (1/4))^2 - 1/16 + (y- 1)^2 - 1 = 127/16$

[kindred lichen]

AsianFailure

[night yacht]

,tex $(x + (1/4))^2 + (y- 1)^2 = 127/16 + 1/16 + 1$

[kindred lichen]

AsianFailure