is there a way to solve this?

• October 21st 2008, 11:02 AM
mathdummy22
is there a way to solve this?
81s^2 - 1 = 0
• October 21st 2008, 11:04 AM
Moo
Hello,
Quote:

Originally Posted by mathdummy22
81s^2 - 1 = 0

Note that $81=9^2$

so it can be written $(9s)^2-1^2=0$

formula for the difference of two squares... ?
• October 21st 2008, 11:04 AM
batman
you have 81s^2=1, or s^2=1/81. Now take square roots to find s=sqrt(1/81) or s=-sqrt(1/81). So s=1/9 or s=-1/9
• October 21st 2008, 11:08 AM
marionca57
Quote:

Originally Posted by mathdummy22
81s^2 - 1 = 0

I would do the following

81 s^2 - 1- = 0

81s^2 = 1 add 1 to both sides

s^2 = 1/81 divide both sides by 81

s = 1/9 take square root of both sides.

Hope that helps. First time to this site.
Marion