Question

How do you factor the trinomial `k ^2 - 27kj - 90j ^2`?

Answer 1

`(k-30j)(k+3j)`

Explanation:

To factor `k^2-27kj-90j^2`

Begin by finding the factors of `90`
`1 & 90`
`2&45`
`3&30`
`5&18`
`6&15`
`9&10`

Now look at the signs of the trinomial. Since the second sign is negative we need to subtract the factors to get the middle term `27`. The signs of the binomials will need to be `- & +`

This means we will use `30 &3`

Sine the first sign is negative the larger factor will be negative so we will use `-30 & +3`

`(k-30j)(k+3j)`