The equation x^2 + y^2 + 10x - 8y = 59 can be written in the
form (x - h)^2 + (y - k)^2 = r^2, where h, k, and r are integers. Find the value of r^2.
x2 + y2 + 10x – 8y = 59
Rearrange & add parentheses in
preparation to complete squares.
(x2 + 10x ) + (y2 – 8y ) = 59
To find c, if a=1, then c = (b/2)2
(x2 + 10x + 25) + (y2 – 8y + 16) = 59 + 25 + 16
(x + 5)2 + (y – 4)2 = 100 ——>> r2 = 100
.