Answer:
1 / 5
Step-by-step explanation:
5 / 7 of x is 1 / 7
( 5 / 7 ) * x = 1 / 7
x = ( 1 / 7 ) * ( 7 / 5 )
= ( 1 * 7 ) / ( 7 * 5 )
x = 1 / 5