Find the value of `k` such that `x^2+2x+9k-5=0` has both roots negative.

Explanation

For both roots to be negative,

`D ge 0`.

`=>b^2 - 4ac ge 0`

`=>2^2 - 4(9k-5) ge 0`

`=>4-36k+20 ge 0`

`=>k le 24/36=>k le 2/3->(1)`

Also, for roots to be negative, their product should be greater than `0`.
`:. 9k-5 gt 0=> k gt 5/9`

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