Algebra II - Completing the Square 1
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A method called Completing the Square can be used to make any
quadratic expression into a Perfect Square Trinomial. This method can
be used on ANY quadratic equation so that it can be solved using the
Square Root Property.
To complete the square of any quadratic expression ax2 + bx :
 Take half of b (
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b 2 b2
), square it ( ( )  ), and you have the perfect c !
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* The leading coefficient, a, must be 1 for this to work.
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Example 1: Find the value of c that makes a perfect square, then
write the trinomial:
x2 + 12x + c
Solve by completing the square:
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Example 2:
x2 + 8x = 20
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Example 3:
f(x) = x2 – 6x + 25