Multiply 0.75 by 2.8 x 10^-5
To multiply two numbers in scientific notation, you can simply multiply the two decimals together and then multiply the powers of 10 together.
0.75 * 2.8 = 2.1
10^-5 * 10^(unknown power) = 10^-5+unknown power
So, 0.75 × 2.8 × 10^-5 = 2.1 × 10^(-5+unknown power)
Since we don't know the unknown power, we cannot simplify the expression further.