Write the Word or Phrase That Best Completes Each Statement

Essay

Write the word or phrase that best completes each statement or answers the question.
Solve the problem.
- $$\text { If } \left. f ( x ) = x ^ { 2 } \text { and } g ( x ) = - 1 + 5 x \text {, find (f } g \right) ( x ) \text { and find the domain of } ( f \circ g ) ( x )$$