Comparison of Expressions 7 and 8

Oct 13, 2025 by leolavanderia.com.br 21 views

Introduction

In this article, we will evaluate two mathematical expressions and identify the step in which the first mistake appears. We will follow the order of operations (PEMDAS) to evaluate the expressions and determine where the mistake occurs.

Expression 7

The expression given is:

$8 \div 2 + (3 \times 3 - 2)$

Step 1: $8 \div 2$

To evaluate this expression, we need to follow the order of operations (PEMDAS). The first step is to divide 8 by 2.

$8 \div 2 = 4$

Step 2: $3 \times 3$

Next, we need to multiply 3 by 3.

$3 \times 3 = 9$

Step 3: $9 - 2$

Now, we need to subtract 2 from 9.

$9 - 2 = 7$

Step 4: $4 + 7$

Finally, we need to add 4 and 7.

$4 + 7 = 11$

Conclusion

The final answer to the expression $8 \div 2 + (3 \times 3 - 2)$ is 11.

Expression 8

The expression given is:

$8 \div 2 + (3 \times 3 - 2)$

Step 1: $8 \div 2$

To evaluate this expression, we need to follow the order of operations (PEMDAS). The first step is to divide 8 by 2.

$8 \div 2 = 4$

Step 2: $3 \times 3$

Next, we need to multiply 3 by 3.

$3 \times 3 = 9$

Step 3: $9 - 2$

Now, we need to subtract 2 from 9.

$9 - 2 = 7$

Step 4: $4 + 7$

Finally, we need to add 4 and 7.

$4 + 7 = 11$

Conclusion

The final answer to the expression $8 \div 2 + (3 \times 3 - 2)$ is 11.

Comparison of Expressions 7 and 8

Both expressions 7 and 8 are identical. Therefore, the first mistake appears in the same step for both expressions.

Step 1: $8 \div 2$

The first mistake appears in this step because the expression is not properly evaluated. The correct evaluation of the expression is:

$8 \div 2 + (3 \times 3 - 2)$

$= 4 + (9 - 2)$

$= 4 + 7$

$= 11$

However, if we follow the order of operations (PEMDAS), we get:

$8 \div 2 = 4$

$3 \times 3 = 9$

$9 - 2 = 7$

$4 + 7 = 11$

Therefore, the first mistake appears in the step where we evaluate the expression $8 \div 2$ .

Conclusion

In conclusion, the first mistake appears in the step where we evaluate the expression $8 \div 2$ . This is because the expression is not properly evaluated, and the correct evaluation of the expression is:

$8 \div 2 + (3 \times 3 - 2)$

$= 4 + (9 - 2)$

$= 4 + 7$

$= 11$

However, if we follow the order of operations (PEMDAS), we get:

$8 \div 2 = 4$

$3 \times 3 = 9$

$9 - 2 = 7$

$4 + 7 = 11$

$Therefore, the first mistake appears in the step where we evaluate the expression $8 \div 2$.<br/> **Q&A: For Numbers 7 and 8, Identify the Step in Which the First Mistake Appears**$

Introduction

In our previous article, we evaluated two mathematical expressions and identified the step in which the first mistake appears. In this article, we will answer some frequently asked questions related to the topic.

Q: What is the order of operations (PEMDAS)?

A: The order of operations (PEMDAS) is a set of rules that tells us which operations to perform first when we have multiple operations in an expression. PEMDAS stands for:

Parentheses: Evaluate expressions inside parentheses first.
Exponents: Evaluate any exponential expressions next (e.g., 2^3).
Multiplication and Division: Evaluate any multiplication and division operations from left to right.
Addition and Subtraction: Finally, evaluate any addition and subtraction operations from left to right.

Q: Why is it important to follow the order of operations?

A: Following the order of operations is important because it ensures that mathematical expressions are evaluated consistently and accurately. If we don't follow the order of operations, we may get different answers depending on how we evaluate the expression.

Q: What is the difference between an expression and an equation?

A: An expression is a group of numbers, variables, and mathematical operations that are combined using mathematical symbols. An equation, on the other hand, is a statement that says two expressions are equal. For example:

Expression: 2x + 3 Equation: 2x + 3 = 5

Q: How do I identify the step in which the first mistake appears?

A: To identify the step in which the first mistake appears, follow these steps:

Evaluate the expression using the order of operations (PEMDAS).
Check your work to make sure you followed the order of operations correctly.
If you made a mistake, go back and re-evaluate the expression.

Q: What if I'm still having trouble identifying the step in which the first mistake appears?

A: If you're still having trouble identifying the step in which the first mistake appears, try the following:

Break down the expression into smaller parts and evaluate each part separately.
Use a calculator or computer program to evaluate the expression and see if you get the same answer.
Ask a teacher or tutor for help.

Q: Can I use the order of operations to evaluate expressions with multiple operations?

A: Yes, you can use the order of operations to evaluate expressions with multiple operations. For example:

Expression: 2 + 3 × 4 - 5

Using the order of operations, we would evaluate this expression as follows:

Multiply 3 and 4: 3 × 4 = 12
Add 2 and 12: 2 + 12 = 14
Subtract 5 from 14: 14 - 5 = 9

Therefore, the final answer to the expression 2 + 3 × 4 - 5 is 9.

Conclusion

In conclusion, following the order of operations (PEMDAS) is essential for evaluating mathematical expressions accurately. By following the order of operations, we can ensure that mathematical expressions are evaluated consistently and accurately. If you're still having trouble identifying the step in which the first mistake appears, try breaking down the expression into smaller parts and evaluating each part separately.