Question

What is `(7.2 * 10^9)( 3 * 10^-5)`?

Answer 1

Multiply the numbers and add the indices of like bases.
`2.16 xx 10^5`

Explanation:

`7.2 xx 3 =21.6" and "10^9 xx 10^-5 = 10^4`

This gives `21.6*10^4`

Given in scientific notation, this becomes `2.16 xx 10^5`