9x²+4y²-18x+16y-11=0

1 answer

9 x^2 -18 x = -4 y^2 -16 y + 11

x^2 - 2 x = -(4/9) y^2 -(16/9) y + 11/9

x^2 - 2 x + 1 =-(4/9) y^2 -(16/9) y+ 20/9

-(9/4)(x-1)^2 = y^2 + 4 y - 5

-(9/4)(x-1)^2 + 5 + 4 = y^2 + 4 y +4

-(9/4)(x-1)^2 + 9 = (y+2)^2

+ 9 = (9/4)(x-1)^2 + (y+2)^2

(x-1)^2/4 + (y+2)^2/9 = 1

ellipse center at (1,-2) semi axes 2 and 3