If the equation x^2−6x=-k has at least one solution, which of the following must be true?
Pick one:
A) k > 9  B) k < −9  C) k = 9  D) k ≤ 9  E) k ≥ −9
x^2−6x=-k   =&gt; x^2−6x + k = 0   For a quadratic equation to have at least one solution, its discriminant (b^2-4ac) should be non-negative.   b^2-4ac ≥0   =&gt; 36 - 4*1*(-k) ≥0   =&gt; 36 - 4k ≥0   =&gt; k ≤9   Answer k ≤ 9
<result>D</result>
If the equation x^2−6x=-k has at least one solution, which of the following must be true?