Using the laws of exponents simplify and express each of the exponential form with positive exponent : `(3^(-7)-:3^(-10))xx 3^(-5)`

Explanation

`(3^(-7)-:3^(-10))xx 3^(-5)`
Using law of exponents `(a^-m-:a^-n=a^(-m+n)` and `a^-m=1/a^m`
`{(3^-7)/3^-10}xx3^-5`
`{3^(-7+10)}xx1/3^5`
`3^3xx1/3^5`
`3^3/3^5`
`3^(3-5)`
`3^-2`
`1/9`