What Is The Value Of − 3 R + 8 -3r + 8 − 3 R + 8 When R = 4 R = 4 R = 4 ?A. { -12$}$B. { -4$}$C. ${ 4\$} D. ${ 12\$}

What is the Value of $-3r + 8$ when $r = 4$?

Understanding the Problem

In this problem, we are given an algebraic expression $-3r + 8$ and asked to find its value when $r = 4$. To solve this problem, we need to substitute the value of $r$ into the expression and then simplify it.

Substituting the Value of $r$

The first step in solving this problem is to substitute the value of $r$ into the expression. We are given that $r = 4$, so we can replace $r$ with $4$ in the expression:

$$-3r + 8 = -3(4) + 8$$

Simplifying the Expression

Now that we have substituted the value of $r$ into the expression, we can simplify it by following the order of operations (PEMDAS):

1. Multiply $-3$ and $4$: $-3(4) = -12$
2. Add $8$ to $-12$: $-12 + 8 = -4$

Therefore, the value of $-3r + 8$ when $r = 4$ is $-4$.

Conclusion

In conclusion, the value of $-3r + 8$ when $r = 4$ is $-4$. This can be verified by substituting the value of $r$ into the expression and simplifying it.

Answer

The correct answer is:

• B. {-4$}$

Why is this the Correct Answer?

This is the correct answer because we substituted the value of $r$ into the expression and simplified it, resulting in a value of $-4$. This is the only option that matches the value we obtained through substitution and simplification.

What is the Importance of Substitution and Simplification?

Substitution and simplification are essential skills in algebra that allow us to evaluate expressions and solve equations. By substituting values into expressions and simplifying them, we can determine the value of the expression and solve problems. In this case, substitution and simplification allowed us to find the value of $-3r + 8$ when $r = 4$.

How to Apply Substitution and Simplification in Real-World Scenarios

Substitution and simplification are not just limited to algebraic expressions. They can be applied in real-world scenarios, such as:

• Evaluating the cost of a product by substituting the price into a formula
• Determining the area of a room by substituting the dimensions into a formula
• Solving problems in physics, engineering, and other fields that involve algebraic expressions

Conclusion

In conclusion, substitution and simplification are essential skills in algebra that allow us to evaluate expressions and solve equations. By substituting values into expressions and simplifying them, we can determine the value of the expression and solve problems. In this case, substitution and simplification allowed us to find the value of $-3r + 8$ when $r = 4$.
Q&A: Substitution and Simplification in Algebra

Frequently Asked Questions

In this article, we will answer some frequently asked questions about substitution and simplification in algebra.

Q: What is substitution in algebra?

A: Substitution in algebra is the process of replacing a variable in an expression with a specific value. This allows us to evaluate the expression and determine its value.

Q: Why is substitution important in algebra?

A: Substitution is important in algebra because it allows us to evaluate expressions and solve equations. By substituting values into expressions, we can determine the value of the expression and solve problems.

Q: What is simplification in algebra?

A: Simplification in algebra is the process of reducing an expression to its simplest form. This involves combining like terms, removing parentheses, and performing other operations to simplify the expression.

Q: Why is simplification important in algebra?

A: Simplification is important in algebra because it allows us to evaluate expressions and solve equations more easily. By simplifying expressions, we can make them easier to work with and solve.

Q: How do I know when to substitute and simplify?

A: You should substitute and simplify when you are given an expression and asked to evaluate it. This can be in the form of a problem or an equation.

Q: What are some common mistakes to avoid when substituting and simplifying?

A: Some common mistakes to avoid when substituting and simplifying include:

• Not substituting values into expressions correctly
• Not simplifying expressions correctly
• Not following the order of operations (PEMDAS)
• Not combining like terms correctly

Q: How can I practice substitution and simplification?

A: You can practice substitution and simplification by working through problems and exercises in your algebra textbook or online resources. You can also try substituting and simplifying expressions on your own to get more practice.

Q: What are some real-world applications of substitution and simplification?

A: Substitution and simplification have many real-world applications, including:

• Evaluating the cost of a product by substituting the price into a formula
• Determining the area of a room by substituting the dimensions into a formula
• Solving problems in physics, engineering, and other fields that involve algebraic expressions

Q: Can I use substitution and simplification to solve equations?

A: Yes, you can use substitution and simplification to solve equations. By substituting values into equations and simplifying them, you can solve for the unknown variable.

Q: What are some tips for mastering substitution and simplification?

A: Some tips for mastering substitution and simplification include:

• Practicing regularly to build your skills
• Paying attention to the order of operations (PEMDAS)
• Combining like terms correctly
• Checking your work to make sure you have simplified the expression correctly

Conclusion

In conclusion, substitution and simplification are essential skills in algebra that allow us to evaluate expressions and solve equations. By substituting values into expressions and simplifying them, we can determine the value of the expression and solve problems. We hope this Q&A article has helped you understand substitution and simplification better and has provided you with some tips and resources to help you master these skills.