How do i find the answer to 1/9-1/x divided by 1/81-1/x^2
a ^ 2 - b ^ 2 = ( a + b ) ( a - b )
1 / 81 - 1 / x ^ 2 = ( 1 / 9 ) ^ 2 - ( 1 / x ) ^ 2 = ( 1 / 9 + 1 / x ) ( 1 / 9 - 1 / x )
( 1 / 9 - 1 / x ) / ( 1 / 81 - 1 /x ^ 2 ) =
( 1 / 9 - 1 / x ) / [ ( 1 / 9 + 1 / x ) ( 1 / 9 - 1 / x ) ] =
1 / ( 1 / 9 + 1 / x ) =
1 / [ ( x + 9 ) / 9 x ] =
9 x / ( x + 9 )