Answer:
The value of x would be -3.
Step-by-step explanation:
Consider the complete question is,
'Which represents all the values of x that make the rational expression [tex]\frac{-6x + 42}{3x + 9}[/tex] undefined?'
Since, the rational expression is defined for all real values except those for which denominator is equal to zero,
If 3x + 9 = 0,
3x = -9
[tex]\implies x =-\frac{9}{3}=-3[/tex]
Hence the values of x that make the rational expression undefined would be -3.
