Solve x
2 - 4x - 7 = 0 by completing the square. What are the solutions?

{2 + , 2 - }
{-2 + , -2 - }
{2 + , 2 + }

Step-by-step explanation:

First, let's move the to the right-hand side so we can determine what constant we'll need on the left-hand side to complete the square:

From here, since the coefficient of the term is , we know the square will be (since it's half of ).

To complete this square, we will need to add to both sides of the equation:

Now we can take the square root of both sides to figure out the solutions to :

step-by-step explanation:

the multiplicative inverse of a fraction a/b is b/a. for the multiplicative inverse of a real number, divide 1 by the number. for example, the reciprocal of 5 is one fifth 1/5 or 0.2, and the reciprocal of 0.25 is 1 divided by 0.25, or 4.