Write the Word or Phrase That Best Completes Each Statement $$\frac { x ^ { 2 } - 56 } { x ^ { 4 } + 5 x ^ { 2 } - 36 }$$

Essay

Write the word or phrase that best completes each statement or answers the question.
- $$\frac { x ^ { 2 } - 56 } { x ^ { 4 } + 5 x ^ { 2 } - 36 }$$