Question

If using the method of completing the square to solve the quadratic equationx2 + 2x + 30 = 0, which number would have to be added to "complete thesquare"?

Answer 1

Solution

For this case we have the following equation:

$x^2+2x+30=0$

We can complete the square with the following:

$x^2+2x+(\frac{2}{2})^2+30-(\frac{2}{2})^2=0$

And solving we got:

$x^2+2x+1+30-1=0$

Then the answer for this case should be:

1