xover9 = 1/81

So you have:  $${\frac{{\mathtt{x}}}{{\mathtt{9}}}}$$ = $${\frac{{\mathtt{1}}}{{\mathtt{81}}}}$$

Cross-multiply the equation.

x*81 = 9*1

Simplify.

81x = 9

Divide both sides by 81

x = 9/81

Simplify the fraction.

x = 1/9

Hi Kitty,

You could have just multiplied both sides by 9 in the first place. You made it a little longer than necessary.