81s^2 - 1 = 0
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Hello, Originally Posted by mathdummy22 81s^2 - 1 = 0 Note that $\displaystyle 81=9^2$ so it can be written $\displaystyle (9s)^2-1^2=0$ formula for the difference of two squares... ?
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
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
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