Show that the equation represents a circle by rewriting it in standard form, and find the center and radius of the circle.
x^2 + y^2 - 2x + 8y + 1 = 0
standard form
center (x, y) = ( )
radius

center is (1,-4)  

radius is 4

Step-by-step explanation:

standard form is

, where center is (h,k) and r is the radius

apply completing the square method to get standard form

take half of the middle term and square it and then add it on both sides

center is (1,-4)  and r^2 is 16

radius is 4

6.9

step-by-step explanation:

simple math really

6 1/2 times 0.6 = 3.9

but if you are just doing 6 and not 6 1/2 then the answer is 3.6