The given expression is
(1.5 x 10^-5) (3 x 10^2)
We would multiply the terms without the powers of 10 first. Then we would multiply the terms haveing the powers of 10 by applying the following rule
a^b * a^ c = a^(b + c)
Therefore,
1.5 * 3 = 4.5
10^-5 * 10^2 = 10^(- 5 + 2)
= 10^- 3
Therefore, the answer in scientific notation is
4.5 * 10^-3