1. The problem states: "A number added to -6 is -7." We need to write this as an equation using $x$ to represent "a number."\n\n2. The phrase "a number added to -6" means $x + (-6)$ or $x - 6$.\n\n3. The phrase "is -7" means the expression equals $-7$.\n\n4. Putting it all together, the equation is: $$x + (-6) = -7$$\n\n5. We do not simplify as per the instructions.