Answer
$20x^5+24x^3-25x^2-30$
Work Step by Step
Using $(a+b)(c+d)=ac+ad+bc+bd$ or the FOIL Method, the expression, $
(4x^3-5)(5x^2+6)
$, is equivalent to
\begin{array}{l}
4x^3(5x^2)+4x^3(6)-5(5x^2)-5(6)
\\\\=
20x^{3+2}+24x^3-25x^2-30
\\\\=
20x^5+24x^3-25x^2-30
.\end{array}
