9x^2+16y^2+64y+28=0

Question

I am supposed to convert this to standard form, but my answer doesn't make sense. One part was 9x^2/92...does that sound right?

Answer 1

16 y^2 + 64 y = - 9 x^2-28
y^2 + 4 y = (- 9 x^2-28 )/16
y^2 + 4 y + 4 = (- 9 x^2-28 )/16 +64/16
(y+2)^2 = (-9 x^2 + 36 )/16
(y+2)^2 + (9/16) x^2 = 36/16
16/36 (y+2)^2 + 9/36 x^2 = 1

x^2/2^2 + (y+2)^2/(3/2)^2 = 1
ellipse with center at (0,-2)
x half axis length 2
y half axis length = 1.5

Answer 2

Shouldn't it equal zero anyway because what does Y equal?