1. The problem is to simplify the expressions $x-4$ and $x-6$ or to understand their difference. 2. These are linear expressions representing values decreased by 4 and 6 respectively from $x$. 3. To find the difference between the two expressions, subtract one from the other: $$ (x-4) - (x-6) $$ 4. Simplify the subtraction: $$ x - 4 - x + 6 $$ 5. Cancel out $x$ terms: $$ \cancel{x} - 4 - \cancel{x} + 6 $$ 6. Combine like terms: $$ -4 + 6 = 2 $$ 7. So, the difference between $x-4$ and $x-6$ is 2. This means $x-4$ is always 2 more than $x-6$ for any value of $x$.