Answer
$2x^5+x^4-6x-3$
Work Step by Step
RECALL:
$(a+b)(c+d)=ac+ad+bc+bd$ (more popularly known as the FOIL method)
Use the FOIL method to obtain:
$(x^4-3)(2x+1)
\\=x^4(2x) + x^4(1) + (-3)(2x)+(-3)(1)
\\=2x^5+x^4+(-6x)+(-3)
\\=2x^5+x^4-6x-3$
