Simplify the expression 2a - 3a + 4.

Simplify the expression 2a - 3a + 4.

• A. -a - 4
• B. a + 4
• C. -5a + 4
• D. -a + 4

Answer: (D)

Combining like terms by adding coefficients is the main idea. The expression has two terms with a: 2a and -3a. Add their coefficients: 2 + (-3) = -1, so that part becomes -a. The constant 4 stays as is. Put together, the simplified expression is -a + 4. Options that would mis-handle this include treating the a terms as if they multiply to -5a, which isn’t the case because you’re adding coefficients, not multiplying. Or dropping the a term and leaving just 4, or changing the sign of the constant. The correct form preserves the -a from combining the a terms and keeps the +4 as the constant.

Combining like terms by adding coefficients is the main idea. The expression has two terms with a: 2a and -3a. Add their coefficients: 2 + (-3) = -1, so that part becomes -a. The constant 4 stays as is. Put together, the simplified expression is -a + 4.

Options that would mis-handle this include treating the a terms as if they multiply to -5a, which isn’t the case because you’re adding coefficients, not multiplying. Or dropping the a term and leaving just 4, or changing the sign of the constant. The correct form preserves the -a from combining the a terms and keeps the +4 as the constant.