Answer :

To determine which value of [tex]\( x \)[/tex] makes the rational expression [tex]\(\frac{16-x}{7+x}\)[/tex] undefined, we need to identify when the denominator is zero. A rational expression becomes undefined when its denominator equals zero, as division by zero is undefined.

Let’s examine the denominator [tex]\( 7 + x \)[/tex]:

1. Set the denominator equal to zero:
[tex]\[ 7 + x = 0 \][/tex]

2. Solve for [tex]\( x \)[/tex]:
[tex]\[ x = -7 \][/tex]

Therefore, the value of [tex]\( x \)[/tex] that makes the denominator zero, and thus the rational expression undefined, is [tex]\( -7 \)[/tex].

So, the correct answer is:

B. [tex]\(-7\)[/tex]