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Assuming $a \neq 3, b \neq 4$, and $c \neq 5$, what is the value in simplest form of the following expression? (Adapted From 2020 AMC 10A Problems, Question \#3)  $$ \frac{2a-6}{5-c} \cdot \frac{b-4}{3-a} \cdot \frac{2c-10}{4-b} $$ 
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If $x \neq y$, then $\frac{x-y}{y-x}=-1$. We use this fact to simplify the original expression: $$ \frac{2a-6}{5-c} \cdot \frac{b-4}{3-a} \cdot \frac{2c-10}{4-b} = -2\times 2= 4$$. 