Answer:
8a^10
Step-by-step explanation:
First know that if you multiply two exponents with same base you add the two base.
So, 2^7*2^3=2^10
Then calculate.
4a^7*2a^3
=4*2*(a^7*a^3)
=4*2*(a^10)
=8*(a^10)
=8*a^10
