Question

17/42:[(1/5+1/5•1/9):7/30-1/3]=

Answer 1

17/42 : [(1/5 + 1/5 * 1/9) : 7/30 - 1/3] =
17/42 : [(⁹⁾1/5 + 1/45) : 7/30 - 1/3] =
17/42 : [(9/45 + 1/45) :7/30 - 1/3] =
17/42 : [10/45 * 30/7 - 1/3] =
17/42 : [20/21 - ⁷⁾1/3] =
17/42 : [20/21 - 7/21] =
17/42 : 13/21 =
17/42 * 21/13 = 
17/26

Answer 2

= 17/42:[(1/5+1/45):7/30-1/3]
=17/42:[(9/45+1/45):7/30-1/3]
= 17/42:[10/45:7/30-1/3]
=17/42:[ 10/45 x 30/7-1/3]
=17/42:[10/3x2/7-1/3]
=17/42:[20/21-1/3]
=17/42:[20/21-7/21]
=17/42: 13/21
= 17/42x21/13
= 17/2 x 1/13
=17/26