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A Brief Intro

TRY IT:

Find a, b and c:  -3x^2 - x - 5 = 0

Find a, b and c:  x^2 - 6 = 0

Also, the variable doesn't have to be x. It can be any letter. x is just our standard unknown variable guy.

So, what kind of answers will we get for these things?

Remember when you solved equations like this?

2x - 3 = 5

Solve it!

2x - 3 = 5 ... add 3 to both sides, which gives 2x = 8 ... divide both sides by 2, which gives x = 4

We always got ONE answer. Right?

What's the power on the x guy?

2x - 3 = 5 is 2x^1 - 3 = 5

With quadratics, we've got a max power of two.

x^2 - x - 6 = 0

So, we'll usually get two answers. You'll see.