(-3/7)+(+1/5)+(+2/7)+(-1又1/5)
=-15/35+7/35+10/35+(-42/35)
=-40/35
=-8/7
(-3又5/7)+9+15.5)+(6又2/7)+(-5又1/2)
=-26/7+9+30/2+44/7+(-11/2)
=44/7-26/7+9+30/2+(-11/2)
=18/7+9+19/2
=36/14+9+133/14
=169/14+9
=295/14
-5+(-5)=-10
-20+10=-10
-5+(-5)=-20+10
(-3/7)+(+1/5)+(+2/7)+(-1又1/5)
=-15/35+7/35+10/35+(-42/35)
=-40/35
=-8/7
(-3又5/7)+9+15.5)+(6又2/7)+(-5又1/2)
=-26/7+9+30/2+44/7+(-11/2)
=44/7-26/7+9+30/2+(-11/2)
=18/7+9+19/2
=36/14+9+133/14
=169/14+9
=295/14
-5+(-5)=-10
-20+10=-10
-5+(-5)=-20+10