Question

How do you solve the quadratic `x^2+9x+20=0` using any method?

Answer 1

`x=-4` or `x=-5`

Explanation:

Note that `4+5=9` and `4*5=20`

So: `0 = x^2+9x+20 = (x+4)(x+5)`

Hence zeros: `-4, -5`