How do you solve x^2 + 9x + 9 = 0? Algebra Quadratic Equations and Functions Quadratic Functions and Their Graphs 1 Answer 冠廷 李. Jun 20, 2016 x=(-9+-3sqrt5)/2 Explanation: x^2+9x=-9 x^2+9x+81/4=-9+81/4 (x+9/2)^2=45/4 (x+9/2)=(+-3sqrt5)/2 x=(-9+-3sqrt5)/2 Answer link Related questions What are the important features of the graphs of quadratic functions? What do quadratic function graphs look like? How do you find the x intercepts of a quadratic function? How do you determine the vertex and direction when given a quadratic function? How do you determine the range of a quadratic function? What is the domain of quadratic functions? How do you find the maximum or minimum of quadratic functions? How do you graph y=x^2-2x+3? How do you know if y=16-4x^2 opens up or down? How do you find the x-coordinate of the vertex for the graph 4x^2+16x+12=0? See all questions in Quadratic Functions and Their Graphs Impact of this question 3961 views around the world You can reuse this answer Creative Commons License