How do you solve x^2-20=0 using the quadratic formula?

1 Answer
Patrick H.
Jul 25, 2016

Substitute the variables for the numbers in the equation to get your answer, (+-4sqrt(5))/(2).

Explanation:

The quadratic formula is this: (-b+-sqrt(b^2-4ac))/(2a). In the case of our equation, a=1, b=0, and c=-20. The equation now looks like this: (-0+-sqrt(0^2-4(1)(-20)))/(2(1)). We now simplify the equation to get (+-sqrt(80))/(2). 80 is not a square root, but we can simplify this even further. 16 is a square root and a factor of 80. We now get (+-4sqrt(5))/(2). This is our answer.

Related questions
See all questions in Quadratic Formula
Impact of this question
3739 views around the world
You can reuse this answer
Creative Commons License