Conic 9x²+16y²-18x+64y-71=0. Standard form and type?
(x-1)²/16 + (y+2)²/9 = 1, ellipse
(x-1)²/25 + (y+2)²/16 = 1, ellipse
(x-1)²+1(y+2)²=36, circle
(x-1)²/9 + (y+2)²/16 = 1, ellipse