Answer:
4a^4·b^5
Step-by-step explanation:
The applicable rule of exponents is ...
(x^a)(x^b) = x^(a+b)
The commutative and associative properties of multiplication apply, so we can write the expression as ...
4·(a^3·a)·(b^2·b^3) = 4·a^(3+1)·b^(2+3) = 4·a^4·b^5