Why does completing the square work

What is the perfect square formula? Why is completing the square useful? What does completing the square give you? What are the three steps for solving a quadratic equation? How do you teach completing the square? What does it mean to solve a quadratic equation? Why do we solve quadratic equations? What are the steps to solving a quadratic equation?

What are roots of a quadratic equation? How many roots does the equation x2 2x 1 0? How do you solve equations on a calculator? How do you solve a quadratic equation on a calculator FX EX?

If a , the leading coefficient the coefficient of the x 2 term , is not equal to 1 , divide both sides by a. Add the square of half the coefficient of the x -term, b 2 a 2 to both sides of the equation. Take the square root of both sides. Perhaps just cleaning those up will help you.

Do you see why you can make that change? Notice that my third and fourth terms cancel each other out. If it's wrong please follow the note. Show 1 more comment. Active Oldest Votes. Add a comment. David G. Stork David G. Stork I now that already. The question asks how is line 3 possible? Ross Millikan Ross Millikan k 26 26 gold badges silver badges bronze badges.

Luckily for you, completing the square can be used to solve any quadratic equation, so as long as the practice questions are quadratics, you can use them! If you scroll to the bottom, they have quadratic equation practice questions broken up into categories by difficulty. Khan Academy has an excellent video series on solving quadratic equations, including one video dedicated to showing you how to complete the square.

YouTube also has some great resources, including this video on completing the square and this video that shows you how to tackle more advanced quadratic equations. If you want to check your work, there are some completing the square calculators available online.

A good place to start is mastering systems of equations, which will help you brush up on your fundamental algebra skills, too. One of the most helpful math study tools is a chart of useful mathematical equations. Luckily for you, we have a master list of the 31 formulas you must know to conquer the ACT. If you think you need a more comprehensive study tool , test prep books are one way to go.

As a content writer for PrepScholar, Ashley is passionate about giving college-bound students the in-depth information they need to get into the school of their dreams. Our new student and parent forum, at ExpertHub. See how other students and parents are navigating high school, college, and the college admissions process. Ask questions; get answers. How to Get a Perfect , by a Perfect Scorer.