5/2+9/4-5/1+9/1 15/3+6/5+15/2 11/5+2/1-11/4 21/16-16/3-16/1

5/2+9/4-5/1+9/1 15/3+6/5+15/2 11/5+2/1-11/4 21/16-16/3-16/1
5/2+9/4-5/1+9/1 15/3+6/5+15/2 11/5+2/1-11/4 21/16-16/3-16/1

5/2+9/4-5/1+9/1 15/3+6/5+15/2 11/5+2/1-11/4 21/16-16/3-16/1
5/2+9/4-5/1+9/1
=(2/5-1/5)+(4/9+1/9)
=1/5+5/9
=9/45+25/45
=34/45;
15/3+6/5+15/2
=(3/15+2/15)+5/6
=5/15+5/6
=1/3+5/6
=2/6+5/6
=7/6;
11/5+2/1-11/4
=(5/11-4/11)+1/2
=1/11+1/2
=2/22+11/22
=13/22;
21/16-16/3-16/1
=16/21-(1/16+3/16)
=16/21-1/4
=64/84-21/84
=43/84;
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