Question 607124
x^2+4y^2+6x+16y+9=0
use completing the square method
x^2+6x+4(y^2+4y)=-9
x^2+6x+9+4(y^2+4y+4)=-9+9+16
(x+3)^2+4(y+2)^2=16
(x+3)^2/16+4(y+8)^2/16=16/16
(x+3)^2/16+(y+8)^2/4=1 this is the standard form of  x^2+4y^2+6x+16y+9=0(ellipse)