Answer :
ANSWER
See below
EXPLANATION
Given
[tex]f(x) = \frac{ {x}- 9 }{x + 5} [/tex]
and
[tex]g(x) = \frac{ - 5x - 9}{x - 1} [/tex]
[tex](f \circ \: g)(x)= \frac{ (\frac{ - 5x - 9}{x - 1})- 9 }{(\frac{ - 5x - 9}{x - 1} )+ 5} [/tex]
[tex](f \circ \: g)(x)= \frac{ \frac{ - 5x - 9 - 9(x - 1)}{x - 1}}{\frac{ - 5x - 9 + 5(x - 1)}{x - 1} } [/tex]
Expand:
[tex](f \circ \: g)(x)= \frac{ \frac{ - 5x - 9 - 9x + 9}{x - 1}}{\frac{ - 5x - 9 + 5x - 5}{x - 1} } [/tex]
[tex](f \circ \: g)(x)= \frac{ \frac{ - 5x - 9x + 9 - 9}{x - 1}}{\frac{ - 5x + 5x - 5 - 9}{x - 1} } [/tex]
[tex](f \circ \: g)(x)= \frac{ \frac{ - 14x }{x - 1}}{\frac{ -14}{x - 1} } [/tex]
Since the denominators are the same, they will cancel out,
[tex](f \circ \: g)(x)= \frac{ - 14x}{ - 14} = x[/tex]