Which of the following shows an expression equivalent to the product of two complex numbers, 5i * 4i?

Answer 1

The product of two complex numbers, 5i * 4i, can be calculated by multiplying the real parts and the imaginary parts separately.

The real part of 5i is 0, and the real part of 4i is also 0. So, their product will have a real part of 0.

The imaginary part of 5i is 5, and the imaginary part of 4i is 4. So, their product will have an imaginary part of -20.

Therefore, the expression that represents the product of two complex numbers 5i * 4i is 0 - 20i, which is equivalent to -20i.