[tex](-5a^3bc^2)\cdot(-3abc)=((-5)(-3))(a^3a)(bb)(c^2c)\\\\=15a^{3+1}b^{1+1}c^{2+1}=\boxed{15a^4b^2c^3}\\\\\text{used}\\\\a^n\cdot a^m=a^{n+m}\\\\a=a^1\\\\a\cdot b=b\cdot a\ (commutative\ property)\\\\(a\cdot b)\cdot c=a\cdot(b\cdot c)\ (associative\ property)[/tex]
