To multiply the complex numbers 2i and 5i, we follow the basic rules of multiplication.
First, multiply the coefficients and the imaginary unit separately:
- Coefficients: 2 * 5 = 10
- Imaginary units: i * i = i²
Now, we know that i² is equal to -1. Therefore, we can substitute:
10 * i² = 10 * -1 = -10
So, the product of 2i and 5i simplifies to -10.
In conclusion, when multiplying 2i and 5i, the final answer is -10.