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Course: Algebra (all content) > Unit 9
Lesson 3: Solving quadratics by taking square roots- Solving quadratics by taking square roots
- Solving quadratics by taking square roots
- Quadratics by taking square roots (intro)
- Quadratics by taking square roots
- Quadratics by taking square roots: strategy
- Quadratics by taking square roots: with steps
- Solving simple quadratics review
- Solving quadratics by taking square roots: challenge
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Solving simple quadratics review
Simple quadratic equations like x^2=4 can be solved by taking the square root. This article reviews several examples and gives you a chance to practice on your own.
In general, a quadratic equation can be written as:
In this article, we review how to solve quadratics that are solvable by taking the square root—no fancy factoring or quadratic equations here; we'll get to that technique later.
Example 1
We're given and asked to solve for .
We can show our work like this:
So our two solutions are:
Notice the symbol we included when taking the square root of both sides. This symbol means "plus or minus," and it is important because it ensures we catch both solutions. Want a deeper explanation? Check out this video.
Let's check both solutions:
Yes! Both solutions check out.
Example 2
We're given and asked to solve for .
We can show our work like this:
So our two solutions are:
Let's check both solutions:
Yep! Both check out.
Want to learn more about these types of problems? Check out this video.
Want more practice? Check out this exercise
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