Which Equation Can Be Used To Solve For The Unknown Number?Seven Less Than A Number Is Thirteen.A. N − 7 = 13 N - 7 = 13 N − 7 = 13 B. 7 − N = 13 7 - N = 13 7 − N = 13 C. N + 7 = 13 N + 7 = 13 N + 7 = 13 D. N + 13 = 7 N + 13 = 7 N + 13 = 7

Solving for the Unknown Number: A Mathematical Equation

Mathematics is a fundamental subject that deals with numbers, quantities, and shapes. It is used to solve problems, make predictions, and understand the world around us. In this article, we will focus on solving for an unknown number using a mathematical equation. We will analyze a given problem and determine the correct equation to use.

Seven less than a number is thirteen. This is a simple problem that can be solved using basic algebra. We need to find the value of the unknown number.

Let's break down the problem and understand what it means. "Seven less than a number" means that we need to subtract 7 from the unknown number. This can be represented as:

n - 7

The problem states that this expression is equal to 13. Therefore, we can write the equation as:

n - 7 = 13

Now, let's evaluate the given options to determine which one is correct.

Option A: $n - 7 = 13$

This option matches the equation we derived from the problem. It correctly represents the relationship between the unknown number and the given value.

Option B: $7 - n = 13$

This option is incorrect because it represents the opposite of the problem. Instead of subtracting 7 from the unknown number, it subtracts the unknown number from 7.

Option C: $n + 7 = 13$

This option is also incorrect because it adds 7 to the unknown number instead of subtracting it.

Option D: $n + 13 = 7$

This option is incorrect because it adds 13 to the unknown number and sets it equal to 7, which is not what the problem states.

Based on our analysis, the correct equation to use is:

n - 7 = 13

This equation accurately represents the problem and can be used to solve for the unknown number.

To solve for the unknown number, we can add 7 to both sides of the equation:

n - 7 + 7 = 13 + 7

This simplifies to:

n = 20

Therefore, the value of the unknown number is 20.

Solving for an unknown number is a fundamental concept in mathematics that has many real-world applications. For example, in finance, it can be used to calculate interest rates or investment returns. In science, it can be used to measure the speed of an object or the distance between two points. In engineering, it can be used to design and optimize systems.

When solving for an unknown number, make sure to:

• Read the problem carefully and understand what it is asking for.
• Identify the variables and constants in the equation.
• Use algebraic manipulations to isolate the unknown number.
• Check your solution by plugging it back into the original equation.

By following these tips and tricks, you can become proficient in solving for unknown numbers and apply mathematical concepts to real-world problems.

When solving for an unknown number, some common mistakes to avoid include:

• Not reading the problem carefully and misunderstanding the question.
• Not identifying the variables and constants in the equation.
• Not using algebraic manipulations to isolate the unknown number.
• Not checking the solution by plugging it back into the original equation.

By being aware of these common mistakes, you can avoid them and become a more confident and proficient problem solver.

In conclusion, solving for an unknown number is a fundamental concept in mathematics that has many real-world applications. By understanding the problem, identifying the variables and constants, and using algebraic manipulations, you can solve for the unknown number and apply mathematical concepts to real-world problems. Remember to read the problem carefully, use algebraic manipulations, and check your solution to avoid common mistakes. With practice and patience, you can become proficient in solving for unknown numbers and apply mathematical concepts to real-world problems.
Frequently Asked Questions: Solving for the Unknown Number

In our previous article, we discussed how to solve for an unknown number using a mathematical equation. We analyzed a given problem and determined the correct equation to use. In this article, we will answer some frequently asked questions related to solving for the unknown number.

Q: What is the first step in solving for an unknown number?

A: The first step in solving for an unknown number is to read the problem carefully and understand what it is asking for. This will help you identify the variables and constants in the equation.

Q: How do I identify the variables and constants in the equation?

A: To identify the variables and constants in the equation, look for the letters and numbers that are not equal to each other. The variables are the letters that represent the unknown values, and the constants are the numbers that are not equal to the variables.

Q: What is the difference between a variable and a constant?

A: A variable is a letter that represents an unknown value, and a constant is a number that does not change value. For example, in the equation x + 5 = 10, x is a variable and 5 is a constant.

Q: How do I use algebraic manipulations to isolate the unknown number?

A: To use algebraic manipulations to isolate the unknown number, you can add, subtract, multiply, or divide both sides of the equation by the same value. For example, in the equation x + 5 = 10, you can subtract 5 from both sides to get x = 5.

Q: What is the importance of checking the solution?

A: Checking the solution is important because it ensures that the answer is correct. If you plug the solution back into the original equation and it is true, then you know that the solution is correct.

Q: What are some common mistakes to avoid when solving for an unknown number?

A: Some common mistakes to avoid when solving for an unknown number include:

• Not reading the problem carefully and misunderstanding the question.
• Not identifying the variables and constants in the equation.
• Not using algebraic manipulations to isolate the unknown number.
• Not checking the solution by plugging it back into the original equation.

Q: How can I practice solving for an unknown number?

A: You can practice solving for an unknown number by working on math problems and exercises. You can also use online resources and math apps to help you practice.

Q: What are some real-world applications of solving for an unknown number?

A: Solving for an unknown number has many real-world applications, including:

• Finance: calculating interest rates or investment returns
• Science: measuring the speed of an object or the distance between two points
• Engineering: designing and optimizing systems

In conclusion, solving for an unknown number is a fundamental concept in mathematics that has many real-world applications. By understanding the problem, identifying the variables and constants, and using algebraic manipulations, you can solve for the unknown number and apply mathematical concepts to real-world problems. Remember to read the problem carefully, use algebraic manipulations, and check your solution to avoid common mistakes. With practice and patience, you can become proficient in solving for unknown numbers and apply mathematical concepts to real-world problems.

If you want to learn more about solving for an unknown number, here are some additional resources:

• Online math resources: Khan Academy, Mathway, and Wolfram Alpha
• Math apps: Photomath, Math Tricks, and Math Solver
• Math books: "Algebra" by Michael Artin and "Mathematics for the Nonmathematician" by Morris Kline

• Practice regularly to improve your skills in solving for an unknown number.
• Use online resources and math apps to help you practice.
• Read the problem carefully and understand what it is asking for.
• Identify the variables and constants in the equation.
• Use algebraic manipulations to isolate the unknown number.
• Check your solution by plugging it back into the original equation.

By following these tips and practicing regularly, you can become proficient in solving for unknown numbers and apply mathematical concepts to real-world problems.