Question

Question #d9b53

Answer 1

`(k + 3i)(1 - 7yi) = (k + 21y) + (3 - 7ky)i`

Explanation:

Cross multiply, simplify and group

`(k + 3i)(1 - 7yi) = k + 3i -7kyi -3i*7yi`
`(k + 3i)(1 - 7yi) = k + 3i -7kyi -21*(-1)*y`
`(k + 3i)(1 - 7yi) = k + 3i - 7kyi + 21y`
`(k + 3i)(1 - 7yi) = (k + 21y) + (3 - 7ky)i`