Which is the first step in simplifying the expression 5x + 3 - 2x + 1?

• A. Combine like terms.
• B. Identify constants.
• C. Rearrange the expression.
• D. Factor the expression.

Answer: (A)

The first step in simplifying the expression 5x + 3 - 2x + 1 is to combine like terms. In this expression, we have terms that involve the variable x and constant terms. The terms 5x and -2x are like terms because they both contain the variable x. Similarly, the constants 3 and 1 can also be combined because they do not contain any variables.

By combining the like terms:

• For the variable terms: 5x - 2x results in 3x.

• For the constant terms: 3 + 1 results in 4.

Thus, once we combine these terms, we simplify the original expression to 3x + 4.

This method of combining like terms is foundational in algebra, as it allows for clearer and more manageable expressions. The other options, while related to the process of simplification, do not represent the initial step needed to start simplifying the given expression effectively.