5 - [3/4 +{2 1/ 2 - (1/2 + 1/6 - 1/7 )}]/2 =?

? = 5 - [3/4 + {5/2 - (1/2 + 1/6 - 1/7)}]/2
= 5 - [3/4 + {5/2 - (1/2 + 7 - 6/42 )}]/2
= 5 - [3/4 + {5/2 - (1/2 + 1/42)}]/2
= 5 - [3/4 + {5/2 - (21 + 1/42)}]/2
= 5 - [3/4 + {5/2 - 22/42)}]/2
= 5 - [3/4 + {105 - 22/42)}]/2
= 5 - [3/4 + 83/42]/2 = 5 - [63 + 166/84]/2
= 5 - 229/84/2 = 420 - 229/84/2 = 191/84/2
= 191/84 x 2 = 191/168 = 1²³/₁₆₈