SOLUTION: by completing the square,find in, terms of k, the roots of the equation x^2+2kx-7=0

Algebra ->  Expressions-with-variables -> SOLUTION: by completing the square,find in, terms of k, the roots of the equation x^2+2kx-7=0      Log On


   

Question 1000266: by completing the square,find in, terms of k, the roots of the equation
x^2+2kx-7=0
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
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by completing the square,find in, terms of k, the roots of the equation
x^2 + 2kx - 7 = 0
x^2 + 2kx + ____ = 7
To complete the square, divide the coefficient of x by 2 and square it, add to both sides
x^2 + 2kx + k^2 = 7 + k^2
(x + k)^2 = 7 + k^2
Find the square root of both sides
x + k = +/-sqrt%28k%5E2%2B7%29
x = -k + sqrt%28k%5E2%2B7%29
and
x = -k - sqrt%28k%5E2%2B7%29