Answer :
Hello,
f(-x)=2x^7-2x^6-7x^5-7x^4-4x^3+4x^2 has 2 changing signes.
Maximum possible number of negative roots is 2
f(-x)=2x^7-2x^6-7x^5-7x^4-4x^3+4x^2 has 2 changing signes.
Maximum possible number of negative roots is 2