Geometry: Common Core (15th Edition)

$1$
We start with the given expression: $\frac{2(1-x)}{y-x}$ We plug in the given values for $x$ and $y$: $\frac{2(1-5)}{-3-5}$ The order of operations states that first we perform operations inside grouping symbols, such as parentheses, brackets, and fraction bars. Then, we simplify powers. Then, we multiply and divide from left to right. Then, we add and subtract from left to right. We follow the order of operations to simplify: First, we must simplify inside the inner most grouping symbol, which is the parentheses above the fraction bar. We do so by subtracting: $\frac{2(-4)}{-3-5}$ We finish simplifying above the fraction bar by multiplying: $\frac{-8}{-3-5}$ We simplify below the fraction bar by subtracting: $\frac{-8}{-8}$ Finally, we divide: $1$