Question 1037051
{{{graph(300,200,-5,3,-10,10,2x^3-x^2+16x-5)}}}
The number of positive roots by Descartes Rule of signs is 3 or 1. Graphing shows 1.
f(-x)=-2x^3-x^2-16x-5. No negative roots.  The other two roots must be a conjugate complex pair.
=====================
For the first,
-x^3-x^2+14x-24. There are 2 or 0 positive roots. A table of value or a graph will show no positive roots.
f(-x)=+x^3-x^2-13x-24. There is one negative root.  The other two roots are a conjugate complex pair.
{{{graph(300,200,-10,10,-10,10,-x^3-x^2+14x-24)}}}