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.