Factorize: `6-x-2x^2`

Explanation

By using mid-term splitting:
`6−x−2x^2`
`=−(2x^2+x−6)`
`=−[2x^2+4x−3x−6]`
`=−[2x(x+2)−3(x+2)]`
`=−[(x+2)(2x−3)]`
`=(x+2)(3−2x)`