The difference between two numbers is 9. The first number plus twice the other number is 27. Find the two numbers.

Question image

Understand the Problem

The question is asking to find two numbers based on two conditions: the difference between the two numbers is 9, and the sum of the first number and twice the second number is 27. We will set up equations based on these conditions and solve for the two numbers.

Answer

The two numbers are $15$ and $6$.
Answer for screen readers

The two numbers are $15$ and $6$.

Steps to Solve

  1. Define the Variables

Let the first number be $x$ and the second number be $y$.

  1. Set Up the Equations

Based on the problem:

From the first condition (difference): $$ x - y = 9 $$ From the second condition (sum): $$ x + 2y = 27 $$

  1. Solve for One Variable

From the first equation, we can express $x$ in terms of $y$: $$ x = y + 9 $$

  1. Substitute and Solve

Substitute $x$ in the second equation: $$ (y + 9) + 2y = 27 $$

Combine like terms: $$ 3y + 9 = 27 $$

  1. Isolate the Variable

Subtract 9 from both sides: $$ 3y = 18 $$

Then divide by 3: $$ y = 6 $$

  1. Find the First Number

Now substitute $y$ back into the equation for $x$: $$ x = 6 + 9 = 15 $$

The two numbers are $15$ and $6$.

More Information

The first number ($15$) is greater than the second number ($6$) by $9$, and the first number plus twice the second number equals $27$.

Tips

  • Forgetting to correctly isolate one of the variables before substituting can lead to wrong results.
  • Not carefully combining like terms may also cause errors in solving the equations.

AI-generated content may contain errors. Please verify critical information

Thank you for voting!
Use Quizgecko on...
Browser
Browser