Question

Follow the process of completing the square to solve 2x^2 + 8x - 12 = 0. After adding B^2 to both sides of the equation in step 4, what is the constant on the right side of the equation?
1. -32
2. 112
3. 160

Answer 1

For this case we have the following equation $2x ^ 2 + 8x-12 = 0$

To complete squares we follow the steps below:

We divide between 2 on both sides of the equation:

$x ^ 2 + 4x-6 = 0\\x ^ 2 + 4x = 6$

We divide the term by 2 and square it. We add this to both sides of the equation:

$x ^ 2 + 4x + (\frac {4} {2}) ^ 2 = 6 + (\frac {4} {2}) ^ 2\\x ^ 2 + 4x + (2) ^ 2 = 6 + 4\\x ^ 2 + 4x + (2) ^ 2 = 10\\(x + 2) ^ 2 = 10$

ANswer:

$(x + 2) ^ 2 = 10$