Showing posts with label exponent. Show all posts
Showing posts with label exponent. Show all posts

Friday, March 27, 2009

Dividing exponents

Yesterday we learned that when you multiply exponents you add the number in the exponent, today we see that when you divide exponent you subtract the number in the exponent.

Consider

x7 / 3

What is this equal to?

x*x*x*x*x*x*x / x*x*x = x*x*x*x or x4

x7 / 3 = x7-3 = x4

what about

x3 / 7

= 1 / x7-3 = 1 / x4

We take the reciprocal because the exponent is greater in the divisor, or denominator.

Thursday, March 26, 2009

Exponent

Exponents tell you how many times a factor is multiplied.

x * x * x (x times x times x)

Can be written as x3 or x^3 , when we write the multiplication in this way, we call it an exponent.

To multiply exponents we add them, for example, consider we have

x2 * x3

what is this equal to?

x5

why is this? Well if we write it out, it becomes obvious


x2 * x3

=


(x*x) * (x*x*x) or x5

if we have

5x2 * 2x3

Then the bottom numbers (or base numbers) are multiplied, while the exponents are added


5x2 * 2x3
=
10x5