How do you work out $(2.1times10^8)times(6times10^-5)$ ?

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Answer 1 · 2016-12-10T22:28:31

$12.1 xx 10^-7$

First, group like terms:

$2.1 xx 10^8 xx 6 xx 10^-5$

$(2.1 xx 6) xx (10^8 xx 10^-15)$

Rule for exponents: $color(red)(x^a xx x^b = x^(a+b))$

$12.1 xx 10^(8 - 15)$

$12.1 xx 10^-7$

How do you work out (2.1times10^8)times(6times10^-5)(2.1times10^8)times(6times10^-5)?