Solving Quadratic Equations By Completing The Square | Algebra II | Khan Academy


Solving Quadratic Equations by Completing the Square

Practice this lesson yourself on KhanAcademy.org right now:

Watch the next lesson:

Missed the previous lesson?

Algebra II on Khan Academy: Your studies in algebra 1 have built a solid foundation from which you can explore linear equations, inequalities, and functions. In algebra 2 we build upon that foundation and not only extend our knowledge of algebra 1, but slowly become capable of tackling the BIG questions of the universe. We’ll again touch on systems of equations, inequalities, and functions…but we’ll also address exponential and logarithmic functions, logarithms, imaginary and complex numbers, conic sections, and matrices. Don’t let these big words intimidate you. We’re on this journey with you!

About Khan Academy: Khan Academy is a nonprofit with a mission to provide a free, world-class education for anyone, anywhere. We believe learners of all ages should have unlimited access to free educational content they can master at their own pace. We use intelligent software, deep data analytics and intuitive user interfaces to help students and teachers around the world. Our resources cover preschool through early college education, including math, biology, chemistry, physics, economics, finance, history, grammar and more. We offer free personalized SAT test prep in partnership with the test developer, the College Board. Khan Academy has been translated into dozens of languages, and 100 million people use our platform worldwide every year. For more information, visit join us on Facebook or follow us on Twitter at @khanacademy. And remember, you can learn anything.
For free. For everyone. Forever. #YouCanLearnAnything

Subscribe to Khan Academy’s Algebra II channel:

Subscribe to Khan Academy:

17 thoughts

  1. How come you stuck a four in that gap instead of dragging the neg five there? Totally don’t understand this.

  2. so why is the “2ax” magically not negative since it has  negative sign infront of it? Can anyone explain please.

  3. This says algebra 2 . So I’ve been taking algebra 2 things in 8th grade… wow I’m so mad rn

  4. Hello, and thank you in advance if anybody responds. And peace to all. I am taking a union apprenticeship test tomorrow basis of which is basic algebra, and geometry. i.e. linear distance from fraction to decimal and vice versa. Add/Subtraction unlike terms. Factoring Quad equations and solving quad.following a given formula.
    As far as the geometry its radius, circumference, arc Lengths, parallel lines and transversals. Math was once effortless for me as i see it now in my girls 18,11,6.. Ya i know pray for me.. haha.

  5. at 5:20 why did (x-5)(x+1) get become x=5 and x=-1 and not x=-5 and x=1 like in the problem?

  6. Why was someone with a NAZI handle critiquing others for being unkind? I had to report him.

Comments are closed.