Identify the real and imaginary parts of each complex number. $-4-9i$

• A. $a = -9, b = -4$
• B. $a = -4, b = -9$
• C. $a = 4, b = 9$
• D. $a = -4, b = 9$

Answer: (B)

Verified step by step guidance

1. Understand that a complex number is generally expressed in the form \( a + bi \), where \( a \) is the real part and \( b \) is the imaginary part.
2. Given the complex number \( -4 - 9i \), identify the real part \( a \) and the imaginary part \( b \).
3. The real part \( a \) is the coefficient of the real number, which is \( -4 \) in this case.
4. The imaginary part \( b \) is the coefficient of \( i \), which is \( -9 \) in this case.
5. Therefore, for the complex number \( -4 - 9i \), the real part is \( a = -4 \) and the imaginary part is \( b = -9 \).