How to Check if a Number is a Solution to an Equation

Oct 13, 2025 by wbrum.org 75 views

Introduction

In mathematics, an equation is a statement that asserts the equality of two mathematical expressions. Solving an equation involves finding the value of the variable that makes the equation true. In this article, we will explore how to determine whether a given number is a solution to a given equation. We will use the equation $$x + 19 = 26$$ as an example to illustrate the process.

What is a Solution to an Equation?

A solution to an equation is a value of the variable that makes the equation true. In other words, it is a value that, when substituted into the equation, makes the equation a true statement. For example, if we have the equation $$x + 3 = 7$$, then the solution to the equation is $$x = 4$$, because when we substitute $$x = 4$$ into the equation, we get $$4 + 3 = 7$$, which is a true statement.

Is -7 a Solution to the Equation $x + 19 = 26$ ?

To determine whether -7 is a solution to the equation $$x + 19 = 26$$, we need to substitute -7 into the equation and see if it makes the equation true. We can do this by following the order of operations (PEMDAS):

Evaluate the expression on the left-hand side of the equation: $$-7 + 19$$
Simplify the expression: $$12$$
Evaluate the expression on the right-hand side of the equation: $$26$$
Compare the two expressions: $$12 \neq 26$$

Since the two expressions are not equal, we can conclude that -7 is not a solution to the equation $$x + 19 = 26$$.

Why is -7 Not a Solution to the Equation?

-7 is not a solution to the equation $$x + 19 = 26$$ because it does not satisfy the equation. When we substitute -7 into the equation, we get $$-7 + 19 = 12$$, which is not equal to 26. In other words, -7 does not make the equation true.

How to Check if a Number is a Solution to an Equation

To check if a number is a solution to an equation, you can follow these steps:

Substitute the number into the equation.
Simplify the expression on the left-hand side of the equation.
Evaluate the expression on the right-hand side of the equation.
Compare the two expressions. If they are equal, then the number is a solution to the equation.

Example: Checking if 3 is a Solution to the Equation $x + 5 = 11$

To check if 3 is a solution to the equation $$x + 5 = 11$$, we can follow the steps above:

Substitute 3 into the equation: $$3 + 5 = 11$$
Simplify the expression on the left-hand side of the equation: $$8 = 11$$
Evaluate the expression on the right-hand side of the equation: $$11$$
Compare the two expressions: $$8 \neq 11$$

Since the two expressions are not equal, we can conclude that 3 is not a solution to the equation $$x + 5 = 11$$.

Conclusion

In conclusion, to determine whether a given number is a solution to a given equation, we need to substitute the number into the equation and see if it makes the equation true. We can do this by following the order of operations (PEMDAS) and simplifying the expression on the left-hand side of the equation. If the expression on the left-hand side is equal to the expression on the right-hand side, then the number is a solution to the equation. Otherwise, it is not a solution.

Tips and Tricks

Always follow the order of operations (PEMDAS) when simplifying expressions.
Make sure to simplify the expression on the left-hand side of the equation before comparing it to the expression on the right-hand side.
If the expression on the left-hand side is not equal to the expression on the right-hand side, then the number is not a solution to the equation.

Common Mistakes to Avoid

Not following the order of operations (PEMDAS) when simplifying expressions.
Not simplifying the expression on the left-hand side of the equation before comparing it to the expression on the right-hand side.
Assuming that a number is a solution to an equation without checking it.

Real-World Applications

Solving equations is an essential skill in mathematics and has many real-world applications, such as:
- Physics: Solving equations is used to describe the motion of objects and predict their behavior.
- Engineering: Solving equations is used to design and optimize systems, such as bridges and buildings.
- Economics: Solving equations is used to model economic systems and make predictions about future trends.

Conclusion

Introduction

In our previous article, we explored how to determine whether a given number is a solution to a given equation. In this article, we will answer some frequently asked questions about solving equations.

Q: What is the difference between a solution and a value?

A: A solution to an equation is a value of the variable that makes the equation true. In other words, it is a value that, when substituted into the equation, makes the equation a true statement. For example, if we have the equation $$x + 3 = 7$$, then the solution to the equation is $$x = 4$$, because when we substitute $$x = 4$$ into the equation, we get $$4 + 3 = 7$$, which is a true statement.

Q: How do I know if a number is a solution to an equation?

A: To determine whether a number is a solution to an equation, you can follow these steps:

Substitute the number into the equation.
Simplify the expression on the left-hand side of the equation.
Evaluate the expression on the right-hand side of the equation.
Compare the two expressions. If they are equal, then the number is a solution to the equation.

Q: What if the expressions on both sides of the equation are not equal?

A: If the expressions on both sides of the equation are not equal, then the number is not a solution to the equation. For example, if we have the equation $$x + 3 = 7$$ and we substitute $$x = 5$$ into the equation, we get $$5 + 3 = 8$$, which is not equal to 7. Therefore, $$x = 5$$ is not a solution to the equation.

Q: Can a number be a solution to an equation if it is not an integer?

A: Yes, a number can be a solution to an equation even if it is not an integer. For example, if we have the equation $$x + 3 = 7$$, then the solution to the equation is $$x = 4$$, which is an integer. However, if we have the equation $$x + 3 = 7.5$$, then the solution to the equation is $$x = 4.5$$, which is not an integer.

Q: How do I solve an equation with a variable on both sides?

A: To solve an equation with a variable on both sides, you can follow these steps:

Add or subtract the same value to both sides of the equation to get the variable on one side.
Multiply or divide both sides of the equation by the same value to get the variable on one side.
Simplify the expression on the left-hand side of the equation.
Evaluate the expression on the right-hand side of the equation.
Compare the two expressions. If they are equal, then the equation is solved.

Q: What if I get a negative number as a solution to an equation?

A: If you get a negative number as a solution to an equation, it means that the equation has a negative solution. For example, if we have the equation $$x + 3 = -7$$, then the solution to the equation is $$x = -10$$, which is a negative number.

Q: Can I use a calculator to solve an equation?

A: Yes, you can use a calculator to solve an equation. However, make sure to follow the order of operations (PEMDAS) and simplify the expression on the left-hand side of the equation before comparing it to the expression on the right-hand side.

Q: How do I check if a number is a solution to an equation with multiple variables?

A: To check if a number is a solution to an equation with multiple variables, you can follow these steps:

Substitute the number into the equation.
Simplify the expression on the left-hand side of the equation.
Evaluate the expression on the right-hand side of the equation.
Compare the two expressions. If they are equal, then the number is a solution to the equation.

Conclusion

In conclusion, solving equations is an essential skill in mathematics that has many real-world applications. By following the steps outlined in this article, you can determine whether a given number is a solution to a given equation. Remember to always follow the order of operations (PEMDAS) and simplify the expression on the left-hand side of the equation before comparing it to the expression on the right-hand side.

Tips and Tricks

Always follow the order of operations (PEMDAS) when simplifying expressions.
Make sure to simplify the expression on the left-hand side of the equation before comparing it to the expression on the right-hand side.
If the expression on the left-hand side is not equal to the expression on the right-hand side, then the number is not a solution to the equation.

Common Mistakes to Avoid

Not following the order of operations (PEMDAS) when simplifying expressions.
Not simplifying the expression on the left-hand side of the equation before comparing it to the expression on the right-hand side.
Assuming that a number is a solution to an equation without checking it.

Real-World Applications

Solving equations is an essential skill in mathematics and has many real-world applications, such as:
- Physics: Solving equations is used to describe the motion of objects and predict their behavior.
- Engineering: Solving equations is used to design and optimize systems, such as bridges and buildings.
- Economics: Solving equations is used to model economic systems and make predictions about future trends.