How do you solve the quadratic equation by completing the square: $x^2 - 8x = 7$ ?

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Answer 1 · 2015-07-13T19:25:15

Solve y = x^2 - 8x -7 = 0

$x^2 - 8x = 7$
$x^2 - 8x + 16 = 7 + 16$
$(x - 4)^2 = 23 -> (x - 4) = +- sqrt23$

$x = 8/2 +- sqrt23 = 4 +- sqrt23$

How do you solve the quadratic equation by completing the square: x^2 - 8x = 7x^2 - 8x = 7?