[tex]{ \qquad\qquad\huge\underline{{\sf Answer}}} [/tex]
Here we go ~
For the given function :
[tex]\qquad \sf \dashrightarrow \: f(x) = \dfrac{7}{x - 10} - 7[/tex]
f(x) is defined for all real values of x, except the value of x for which the denominator becomes 0, because if denominator is 0, the function at that instant will be undefined.
that is : f(x) is not defined when :
[tex]\qquad \sf \dashrightarrow \: x - 10 = 0[/tex]
[tex]\qquad \sf \dashrightarrow \: x = 10[/tex]
Hence, f (x) is defined for all real values of x except 10
It can be represented as :
[tex]\qquad \sf \dashrightarrow \: f(x) : x \in R \sim \{10 \}[/tex]