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In this video we're going to discover how to solve quadratics by factorising.
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You should already know what quadratics look like, with an x squared term, an x term and a number on its own.
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Before we look at solving quadratics, you should know how to factorize them first, so you may want to watch these two videos.
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There are a few different ways to solve quadratics.
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Firstly by factorising, or using the quadratic formula or by completing the square.
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In this video we're going to look at solving by factorising.
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You can see how to use a quadratic formula and how to complete the square in these videos.
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Solving just means to find values of x that satisfy the quadratic.
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Usually there will be two solutions but sometimes there is just one and sometimes there are no solutions.
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The solutions are also known as roots.
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When we factorize, we usually end up with two brackets, this is going to give us two roots.
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To solve this factorized quadratic we need it all to equal zero now we can solve.
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Make each bracket equal to zero and solve.
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That's all there is to it x is negative four and x is two.
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If we plotted this quadratic these roots are where the curve crosses the x axis at negative four and up two.
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Here are some questions for you to do.
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Remember you need to factorize first and then solve.
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Pause the video, solve the quadratics click play when you're ready.
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Did you get them right?
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So there, if we looked at the third one on the graph it would look like this with eight here and two here.
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So that is how we solve quadratics by factorising.
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Make the quadratic equal to zero, factorize it and then solve each bracket separately.
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Not all quadratics factorize, which is why we can also solve them using the quadratic formula or by completing the square.
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Watch these videos to discover how.
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If you liked the video give it a thumbs up and don't forget to subscribe.
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Comment below if you have any questions. Why not check out our FuseSchool app as well?
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Until next time!