Difficulty: Moderately Easy
Instructions
Things You'll Need:
- paper
- pen/pencil
- calculator
- quadratic formula
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Step 1
Write out the quadratic equation. It is x=[-b +/- sqrt(b squared-4ac)]/(2a), where x is the root (one of two), a is the coefficient of the x squared term, b is the coefficient of the x term, and c is the constant.
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Step 2
Plug in what you know.
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Step 3
Solve for x. Since it is a quadratic equation, there will be two roots (solutions).
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Step 4
Let's do an example. Solve x squared+3x-10=0 by using the quadratic formula. Here, a=1 (since there is no written coefficient), b=3, and c=-10. Write out the formula: x=[-b +/- sqrt(b squared-4ac)]/2a and plug in the numbers. x=[-3 +/- sqrt(3 squared -4(1)(-10) which simplifies to x=[-3 +/- sqrt(9-(-40))]/2 or [-3 +/- 7]/2. x=-5 or x=2.
