Answer:
Step-by-step explanation:
(x+1)(x+3)(x+5), multiply first two parenthesis
(x² +3x +x +3)(x+5), combine like terms
(x² +4x +3) (x+5), multiply the parenthesis
(x³ +5x² +4x² +20x +3x +15), combine like terms
x³ +9x² +23x +15 is in the form ax³ +bx² +cx +d
a=1, b=9, c=23, d=15 are all positive integers