Question

If x = (10 − 3i) and y = (3 − 10i), then xy= and xy=

Answer 1

`xy=(10-3i)(3-10i)=30-100i-9i-30=-109i`

Answer 2

`xy = -109i`

Explanation:

Given that:

`x = 10 - 3i`

`y = 3-10i`

where, i is the imaginary part

We have to find xy.

`xy=(10-3i)(3-10i)`

⇒
`(10-3i)(3-10i) = 30-100i-9i+30i^2`

We know that:
`i^2 = -1`

then;

⇒
`(10-3i)(3-10i) = 30-100i-9i-30=-109i`

⇒
`xy =-109i`

therefore, the product of x and y is, -109i