algebra

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Determine the value(s) of k for which
x^2+(k-2)x-2k=0
has equal and real roots.

a x^2 + bx + c = 0 has two different roots if the discriminant D defined as:

D = b^2 - 4 a c does not equal zero.

If D = 0 then there is one root. That root is then real if b/a is real. In this case this means that:

(k-2)^2 + 8k = 0 --->

(k+2)^2 = 0 --->

k = -2

k must also be real and -2 is real, so k = -2 is a valid solution.

  • algebra -

    its -3

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