Question

How do you factor the expression `3x^2 + 15x -42`?

Answer 1

Factors are: `(x+7)(3x-6)`

Explanation:

By middle term splitting,
`3x^2+15x-42=0`
`3x^2+21x-6x-42=0`
`3x(x+7)-6(x+7)=0`
`(x+7)(3x-6)=0`
`x=-7` or,`x=2`