How do you evaluate \frac { ( 3.00\times 10^ { 6} ) ( 2.0\times 10^ { - 3} ) } { 5.0\times 10^ { - 2} }(3.00×106)(2.0×103)5.0×102?

2 Answers
Dec 10, 2016

120,000120,000 or 1.2 xx 10^51.2×105

Explanation:

First, rearrange the terms in the numerator:

(3.00 xx 2.0 xx 10^6 xx 10^-3)/(5.00 xx 10^-2)3.00×2.0×106×1035.00×102

Using the rule for exponents where color(red)(x^a xx x^b = x^(a+b))xa×xb=xa+b we can simplify the numerator to:

(6.00 xx 10^(6-3))/(5.0 xx 10^-2)6.00×10635.0×102

(6.00 xx 10^3)/(5.0 xx 10^-2)6.00×1035.0×102

Now using the rule for exponents where color(red)(x^a/x^b = x^(a-b))xaxb=xab we can simplify the fraction to:

(6.00 xx 10^((3 - -2)))/5.06.00×10(32)5.0

(6.00 xx 10^5)/5.006.00×1055.00

Expanding the numerator gives us:

600000/56000005

120000120000

Or in scientific notation form:

1.2 xx 10^51.2×105

Dec 10, 2016

1.2 * 10^51.2105

Explanation:

((3.00 * 10^6)(2.0 * 10^-3))/(5.0 * 10^-2(3.00106)(2.0103)5.0102

multiply out brackets:

(6.0 * 10^3)/(5.0 * 10^-2)6.01035.0102

divide 6 by 5:

(1.2 * 10^3)/10^-21.2103102

and then the powers of 10:

1.2 * 10^51.2105

(reason:) law of indices:
(a^m/a^n = a^(m-n))(aman=amn)

1.21.2 is between 1 and 10, so we do not need to change this or the power of 10.

final answer: 1.2 * 10^51.2105