The problem asks us to find the values of the variables $m$ and $y$ in the given expressions that would make the expressions undefined. This usually happens when the denominator of a fraction is equal to zero.

1. Problem Description

The problem asks us to find the values of the variables $m$ and $y$ in the given expressions that would make the expressions undefined. This usually happens when the denominator of a fraction is equal to zero.

2. Solution Steps

a. For the expression $\frac{12}{4-2m}$, the expression is undefined when the denominator $4-2m$ is equal to

0. $4 - 2m = 0$

$2m = 4$

$m = \frac{4}{2}$

$m = 2$

Therefore, $m$ cannot be

2.

b. For the expression $\frac{y-5}{y+5}$, the expression is undefined when the denominator $y+5$ is equal to

0. $y+5 = 0$

$y = -5$

Therefore, $y$ cannot be -

5.

3. Final Answer

a. $m$ cannot be

2. b. $y$ cannot be -5.