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Hulda Pouros

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3y ago
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14y ago

x2 - 3x -28 = 0

move the constant

x2 - 3x = 28

take half of the x term (1.5), square it (2.25), and add to both sides

x2 - 3x + 2.25 = 2.25 + 28

The left side is now a perfect square, simplify

(x - 1.5)2 = 30.25

Taking the square root of both sides, you find that

x - 1.5 = ±5.5

So...

X1 = 1.5 + 5.5 = 7

X2 = 1.5 - 5.5 = -4

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Q: What is the answer to this equation x² -3x - 28?
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