Question

If using the method of completing the square to solve the quadratic equation x 2 + x + 9 = 0, which number would have to be added to "complete the square"?

Answer 1

Below

Explanation:

To complete the square, the coefficient of x^2 must be 1 ( it is already)

then take 1/2 of the x coefficient .... 1/2.... square it and add it to both sides of the equation

x^2 + x + 1/4 + 9 = 1/4

then you can reduce this to

( x+ 1/2)^2 + 9 = 1/4 for further 'solving'