( 5 8/15 - 4 7/10 ) * 2 2/3 - 5/9 = 1 2/3
1) 5 8/15 - 4 7/10 = 5 16/30 - 4 21/30 = 25/30 = 5/6
2) 5/6 * 2 2/3 = 5/6 * 8/3 = 20/9 = 2 2/9
3) 2 2/9 - 5/9 = 1 6/9 = 1 2/3
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( 5/21 + 5/6 ) * ( 1 2/3 - 3/5 ) * 1 4/5 = 2 2/35
1) 5/21 + 5/6 = 10/42 + 35/42 = 45/42
2) 1 2/3 - 3/5 = 1 10/15 - 9/15 = 1 1/15
3) 45/42 * 1 1/15 = 45/42 * 16/15 = 24/21
4) 24/21 * 1 4/5 = 24/21 * 9/5 = 72/35 = 2 2/35