
William W. answered 10/14/21
Math and science made easy - learn from a retired engineer
You must use "completing the square" to get it into the proper "standard" format.
4x2 + 9y2 + 48x + 72y + 144 = 0
(4x2 + 48x + ) + (9y2 + 72y + ) = -144
4(x2 + 12x + ) + 9(y2 + 8y + ) = -144
4(x2 + 12x + 36) + 9(y2 + 8y + 16) = -144 + 4•36 + 9•16
4(x + 6)2 + 9(y + 4)2 = 144
4(x + 6)2/144 + 9(y + 4)2/144 = 144/144
(x + 6)2/36 + (y + 4)2/16 = 1 or with better formatting: