Question

How do you solve `x^2 + 2x-7=0`?

Answer 1

`x = -1 pm 2sqrt{2}`

Explanation:

Use the quadratic formula for this question where you can't find a master product that will have factors that add to the `b` term.

Quadratic Formula
`x = (-(b) pm sqrt{b^2 - 4ac})/(2a)`

Substitute the values into its corresponding places and evaluate.
`x = (-(2) pm sqrt{2^2 - 4(1)(-7)})/(2(1))`
`x = (-2 pm sqrt{4 + 28})/(2)`
`x = (-2 pm sqrt{32})/(2)`
`x = (-2 pm 4sqrt{2})/(2)`

Simplify the terms (other than the 2 inside of the radical sign) by diving them by the common factor of 2.
`x = (-1 pm 2sqrt{2})/(1)`

Answer: `x = -1 pm 2sqrt{2}`