Simplify the expression 7a + 2a.

Simplify the expression 7a + 2a.

• A. 5a
• B. 9a
• C. 10a
• D. 7a + 2a cannot be simplified

Answer: (B)

To simplify the expression 7a + 2a, you focus on combining like terms. Like terms are terms that have the same variable raised to the same power. In this case, both terms (7a and 2a) involve the variable 'a'. To combine these terms, you simply add their coefficients (the numerical parts) together. The coefficient of the first term is 7, and the coefficient of the second term is 2. Therefore, you add these coefficients together: 7 + 2 = 9. This results in 9a. Thus, 7a + 2a simplifies to 9a, which is why this is the correct choice.

To simplify the expression 7a + 2a, you focus on combining like terms. Like terms are terms that have the same variable raised to the same power. In this case, both terms (7a and 2a) involve the variable 'a'.

To combine these terms, you simply add their coefficients (the numerical parts) together. The coefficient of the first term is 7, and the coefficient of the second term is 2. Therefore, you add these coefficients together:

7 + 2 = 9.

This results in 9a.

Thus, 7a + 2a simplifies to 9a, which is why this is the correct choice.