Question

How do you solve and write the following in interval notation: `(x-4)(x+2)>0`?

Answer 1

`x!in[-2, 4]`

Explanation:

The product > 0. So, the factors are of opposite signs.

If `x-4>0`, then `x+2>0`. These combine to give `x >4`. .

If `x+2<0`, then `x-4<0`. These combine to give `x<-2`.

Thus, `x!in[-2, 4]`