Question

If using the method of completing the square to solve the quadratic equation, which number would have to be added to “complete the square”?

X^2+7x-4=0

Answer 1

Problem

`x^2\text{ + 7x - 4 = 0}`

Step 1:

a = 1 b = 7 and c = -4

Step 2:

The number that you will add to complete the square is square of half of the coefficient of x.

`\begin{gathered} \text{The number that must be added to complete the square} \\ =\text{ }((7)/(2))^2 \\ =\text{ }(49)/(4) \end{gathered}`

The number that you will add to complete the square = 49/4

To solve the equation complete, first move the constant value to the right hand side.

`x^2\text{ + 7x = 4}`

Next, add 49/4 to both sides.