Answer:
3m^3−5m^2+3m+20
Step-by-step explanation:
=(3m+4)(m2+−3m+5)
=(3m)(m2)+(3m)(−3m)+(3m)(5)+(4)(m2)+(4)(−3m)+(4)(5)
=3m3−9m2+15m+4m2−12m+20