Posted by Tyana on Wednesday, October 12, 2011 at 7:31pm.
Find the center (h,k) and the radius (r) of the circle with the given equations:
1. 2(x2)^2+2(y+5)^2=28
2. 4x^2+4y^212x+16y5=0

College Algebra  Steve, Wednesday, October 12, 2011 at 8:06pm
#1 is easy. just read them out of the equation. Divide by 2 to make it easier.
#2: (4x^2  12x) + (4y^2 + 16y) = 5
or
4(x^2  3x) + 4(y^2 + 4y) = 5
(x^2  3x) + (y^2  4y) = 5/4
Now, you need to make the parenthesized terms perfect squares by adding extra constants on both sides of the equation:
(x^2  3x + 9/4) + (y^2  4y + 4) = 5/4 + 9/4 + 4
(x  3/2)^2 + (y  2)^2 = 15/2
now you can read off h,k r^2 from that 
College Algebra  mark, Tuesday, April 24, 2012 at 11:37pm
8,9), x + 2y = 7 please solve this for me