5/6+(-1/3)
=5/6-1/3
=5/6-2/6
=3/6
=1/2
7/9-(-1/27)
=7/9+1/27
=21/27+1/27
=22/27
-8/5+23/50
=-80/50+23/50
=-57/50
45/15-7/3
=9/3-7/3
=2/3
4/11+2
=4/11+22/11
=26/11
-8/91+(-1/7)
=-8/91-13/91
=-21/91
=-3/13
5/2-(-45/4)+2/8
=5/2+45/4+2/8
=20/8+90/8+2/8
=112/8
=56/4
=28/2
=14
4-(-5/49)+(-8/7)
=4+5/49-8/7
=4+5/49-56/49
=4-51/49
=196/49-51/49
=145/49
