The equation of an ellipse is given below.
$\dfrac{x^2}{81}+\dfrac{(y+7)^2}{9}=1$
**What is its center**?
$($[[☃ numeric-input 1]] $,$ [[☃ numeric-input 2]]$)$
**What is its major radius?**
[[☃ numeric-input 3]] units
**What is its minor radius?**
[[☃ numeric-input 4]] units