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Which equivalent equation results when completing the square to solve x2 − 8x + 7 = 0

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(x - 4)² = 9

Step-by-step explanation:

x² - 8x + 7 = 0 ( add 7 to both sides )

x² - 8x = - 7

to complete the square

add ( half the coefficient of the x- term )² to both sides

x² + 2(- 4)x + 16 = - 7 + 16

(x - 4)² = 9 ← equation to be solved

take the square root of both sides

x - 4 = ± $$\sqrt{9}$$ = ± 3 ( add 4 to both sides )

x = 4 ± 3

then solutions are

x = 4 - 3 = 1 or x = 4 + 3 = 7
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