How do you write the answer in scientific notation given (2.1times10^-4)/(8.4times10^-6)?

2 Answers
Apr 16, 2017

2.5xx10^1

Explanation:

(2.1xx10^(-4))/(8.4xx10^(-6))

=0.00021/ 0.0000084

=2100/ 84

=25

=2.5 xx10^1

Apr 16, 2017

2.5 xx 10^1

Explanation:

Use the exponent rule x^m/x^n = x^(m-n)

(2.1 xx 10^-4)/(8.4 xx 10^-6) = 2.1/8.4 xx 10^(-4- -6) = 0.25 xx 10^2

Scientific notation requires a non-zero number to be to the left of the decimal point. This means you need to move the decimal to the right one place which decreases the exponent by 1:

0.25 xx 10^2 = 2.5 xx 10^1