Final answer:
The expression 4 + i(-1) simplifies to 4 - i, which is in the form of a + bi where a is 4 and b is -1. Option d (4 - i(-1)) is equivalent and correct after applying the multiplication rule for negative signs.
Step-by-step explanation:
To simplify the expression 4 + i(-1), we need to distribute the imaginary unit i across the number it's multiplied by. In this case:
4 + i(-1) = 4 - i
The other options do not accurately represent the distribution process.
When it comes to complex numbers, they typically have the form a + bi, where a stands for the real part and bi indicates the imaginary part. Hence, the simplified expression in the form of a + bi would be 4 - i, which corresponds to option d. It's important to remember that when we multiply an imaginary number by -1, it changes the sign in front of the i.