Since 5 is being multiplied by itself 4 times, that part would be written as
5^4 (5 to the power of 4)
And since 4 is being multiplied by itself 3 times, that part would be written as 4^3 (4 to the power of 3)
Then, since they are being multiplied together the final answer in exponential form is 5^4 * 4^3.