Question

Solve x2 + 6x + 7 = 0.

Answer 1

The answer to the question

Answer 2

Answer:

Option b) negative 3 plus or minus square root of 2

Step-by-step explanation:

We are given a quadratic equation:

$x^2 + 6x + 7 = 0$

We use the quadratic formula to find the factors.

$x = \displaystyle\frac{-b \pm \sqrt{b^2-4ac}}{2a},\\\\\text{a, b and c are coeficients of }x^2, x^1, x^0 \text{ respectively.}$

Hence, comparing with the given equation, a = 1, b = 6 and c = 7

$x = \displaystyle\frac{-6 \pm \sqrt{36-28}}{2}\\\\x = \displaystyle\frac{-6 \pm \sqrt{8}}{2}\\\\x = \displaystyle\frac{-6 + 2\sqrt{2}}{2}, \displaystyle\frac{-6 - 2\sqrt{2}}{2}\\\\x = -3 + \sqrt2, x = -3-\sqrt2$