Find the unknown numbers.
One number is nine less than another. Their sum is negative twenty-seven.

• A. $-18$ and $-27$
• B. $-18$ and $-9$
• C. $-27$ and $-9$
• D. $-9$ and $18$

Answer: (B)

Verified step by step guidance

1. Let the two unknown numbers be represented as variables. For example, let the first number be \(x\) and the second number be \(y\).
2. Translate the first statement "One number is nine less than another" into an equation. This can be written as \(x = y - 9\) (assuming \(x\) is the number that is nine less than \(y\)).
3. Translate the second statement "Their sum is negative twenty-seven" into an equation: \(x + y = -27\).
4. Substitute the expression for \(x\) from the first equation into the second equation to get an equation with one variable: \((y - 9) + y = -27\).
5. Simplify and solve the resulting equation for \(y\), then use the value of \(y\) to find \(x\) using the first equation.