multiply and simplify

7^3 X 7^9

7^3 is 7 multiply by itself 3 times

7*7*7=x

7^9 is 7 multiply by itself 9 times
7*7*7*7*7*7*7*7*7=y

You take the answer from 7^3 (x) and multiply it with 7^9 (y) and you get the answer.