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X^2-3x=7/4
Solve by completing the square

1 Answer

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Answer:

Explanation:

X^2-3x=7/4 should first be rewritten in standard form, which here would be:

x^2 - 3x - 7/4 = 0.

1. Identify the coefficient of the x term and take half of that number:

-3/2

2. square this result: (-3/2)^2 = 9/4

3. add this last result, 9/4, between the -3x term and the -7/4 term, and then subtract it as shown:

x^2 - 3x + 9/4 - 9/4 - 7/4 = 0

4. Rewriting the first 3 terms as the square of a binomial, we get:

(x - 3/2)^2 - 16/4 = 0, or (x - 3/2)^2 = 16/4

5. Take the square root of both sides, obtaining:

x - 3/2 = ±√4/2 or ±√2

6. Write out the two roots: x = 3/2 + √2

and x = 3/2 - √2

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