Question

Solve for x in the equation x^2+ 4x-4=8.

Answer 1

Answer:

x = -6 or x = 2

Step-by-step explanation:

The given equation is:

$x^{2}+4x-4=8\\\\ x^2+4x-4-8=0\\\\ x^2+4x-12=0$

This is quadratic equation, so we can use the quadratic formula to find the roots of the equation i.e. the value of x that satisfy the given equation.

According to the quadratic formula, the two roots will be:

$x=\frac{-b \pm \sqrt{b^{2}-4ac}}{2a}$

Here,

a = coefficient of x² = 1

b = coefficient of x = 4

c = constant term = -12

Using these values, we get:

$x=\frac{-4 \pm \sqrt{(4)^2-4(1)(-12)}}{2(1)}\\\\ x=\frac{-4 \pm \sqrt{64}}{2}\\\\ x=\frac{-4 \pm 8}{2}\\\\ x = \frac{-4-8}{2} , x = \frac{-4+8}{2}\\\\ x=-6, x = 2$

Thus, the two values of x that satisfy the given equation are: -6 and 2. So 1st option gives the correct answer.