Jse Descartes' Rule of Signs to analyze the number of positive and negative real roots and the number of non-real roots of the function: h(x) = -7x° + 7x° – 9x4 + 12x – 72? + 3x – 18 There are at...

I tried solving it and I got this.. BUT it says it's incorrect.. could you please solve it for me? Thank you

There are at least 6 and at most 6 positive real roots.
There are at least  6 and at most 6 negative real roots.
There are at least 6 and at most 0 non-real roots.

Extracted text: Jse Descartes' Rule of Signs to analyze the number of positive and negative real roots and the number of non-real roots of the function: h(x) = -7x° + 7x° – 9x4 + 12x – 72? + 3x – 18 There are at least and at most positive real roots. There are at least and at most negative real roots. There are at least and at most non-real roots.