The given polynomial is:
[tex]30x^3-13x^2-40x-12[/tex]
Substitute x = -2/5 into the expression:
[tex]30\left(-\frac{2}{5}\right)^3-13\left(-\frac{2}{5}\right)^2-40\left(-\frac{2}{5}\right)-12=0[/tex]
Therefore by the remainder theorem x = -2/5 is a root.
[tex]\begin{gathered} x=-\frac{2}{5} \\ multiply\text{ both sides by 5} \\ 5x=-2 \\ 5x+2=0 \end{gathered}[/tex]
Hence, the factor is
5x + 2
A
