Question

How do you solve `1 - 4x - x^2=0` using completing the square?

Answer 1

Solve y = - x^2 - 4x + 1 = 0

Explanation:

`y = - (x^2 + 4x - 1) = 0`

`(x^2 + 4x + 4) - 4 - 1 = 0`
`(x + 2)^2 = 5`
`(x + 2) = +-sqrt5`

`x = - 2 +- sqrt5`