To find the sum of the complex numbers 4i and 10 + 5i, we start by identifying the real and imaginary parts of each number.
The first number, 4i, can be expressed as:
- Real part: 0
- Imaginary part: 4
The second number, 10 + 5i, has:
- Real part: 10
- Imaginary part: 5
Now, we can add the corresponding parts:
- Real part: 0 + 10 = 10
- Imaginary part: 4 + 5 = 9
Thus, the result of the addition is:
10 + 9i
This means the sum of 4i and 10 + 5i is 10 + 9i, where 10 is the real part and 9i is the imaginary part.