-5/2+ 3/8=-5*4/2*4+3*1/8*1=-20/8+3/8=-17/8=-2целые 1/8
7/15+ (-2/5)=7*1/15*1+ (-2*3/5*3)=7/15+(-6/15)=7/15-6/15=1/15
-1/8+3/5=-1/8+3/5=-1*5/8*5+3*8/5*8=-5/40+24/40=19/40
5/8+ (-1/4)=5*1/8*1+(-1*2/4*2)=5/8+(-2/8)=3/8
-3/5+2/5=-1/5
5/16+ (- 2/3)=5*3/16*3+(-2*16/3*16)=15/48+(-32/48)=-17/48