1. The question asks: "Where did the second 5 come from?" This usually refers to an expression or equation where the number 5 appears twice. 2. To answer this, we need to see the original problem or equation where the second 5 appears. 3. Often, the second 5 comes from a step such as distributing, factoring, or rewriting terms. 4. Without the original equation or expression, the best explanation is that the second 5 is introduced by an operation like addition, multiplication, or substitution. 5. If you provide the original equation or step where the second 5 appears, I can explain exactly how it came about.