Question

X ^ 2 + 4x - 7 = 0

Solve using the Quadratic Formula

Answer 1

There's a special case of the quadratic formula called the Shakespeare Quadratic Formula (2b or -2b) that applies when the linear coefficient is even.

`x^2-2Bx + C \textrm{ has zeros }x = B \pm√(B^2 - C)`

If you're planning on solving a lot of quadratic equations quickly, it's good to know.

Here we have

`x^2 + 4x - 7 = 0`

so

`x = -2 \pm √(2^2 - -7)`

`x = -2 \pm √(11)`