(x+10)^2/100 + (y6)^2/81 =1
and how do you know?
and how do you know?

It's an ellipse with its center at the point (10,6). Its an ellipse because of the plus sign. It would be a hyperbola if it was
(x + 10)²/100  (y  6)²/81 = 1
(x + 10)²/100  (y  6)²/81 = 1