Answer
The domain of the given function is the set of all real numbers except $\frac{-3}{7}$.
Work Step by Step
When the question asks for the domain of the function, it is asking for what values of x can be legally substituted into the function. (For instance, in the function $\frac{2}{x}$, x $\ne$ 0, for this would make the denominator of the fraction equal to 0.)
Look for the number that makes the denominator zero by equating the denominator to 0:
$7x+3=0
\\7x = 0-3
\\7x=-3
\\x = \frac{-3}{7}$
Thus, when $x=\frac{-3}{7}$, the denominator is equal to zero.
Therefore, the domain of the given function is the set of all real numbers except $\frac{-3}{7}$.
