Question 208395
The key to working with negative exponents is to understand the basic equation:
{{{x^(-n) = (x^n)^(-1) = (x^n/1)^-1 = 1/(x^n)}}}
In short, a negative exponent means "reciprocal of". In other words, flip the expression upside down and remove the minus sign on the exponent.<br>
So your expression
{{{(3x)^-2}}} means the reciprocal of {{{(3x)^2}}}
So we can rewrite {{{(3x)^-2}}} as {{{1/(3x)^2}}}
Now all we need to do is simplify:
{{{(3x)^-2 = 1/(3x)^2 = 1/(9x^2)}}}