Answer:
D. y^3+2
Step-by-step explanation:
Descartes' rule of signs tells you there are no positive real roots. That eliminates choices A, B, and C, leaving only choice D.
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Pairs of coefficients are in the ratio 5:4 suggesting that factoring by grouping can be effective.
(5y^4 +4y^3) +(10y +8)
= y^3(5y +4) +2(5y +4)
= (y^3 +2)(5y +4)
