Simplify:#(a) x^2×x^4##(b) y^3×y^6##(c) n^13×n^(-7)##(d) a^9×a^3##(e) a^(-2)×3a^4##(f)(2n)^3×(2n)^5##(g) x^16÷n^12##(h) a^15÷a^14##(i) a^2×b^2×a^4#