Răspuns:
d) 4/9+1/6=2/9+1/3=2×1, 9×3=2/27
7/12+5/18=7×5, 12×18=35/216
11/20+3/8=11×3, 20×8=33/160
9/20+5/12=9/4+1/12=9×1+4×12=9/48=3/16
9/24+7/16+5/8=9×7, 24×16+5/8=63/384+5/8=315/3072
e)7/12-3/6=7×1, 4×6=7/24
7/8-7/10=7×7, 8×10=49/80
17/20-11/30=17×11, 20×30=187/600
27/45-13/30=9/45-13/10=9×13, 45×10=117/450=13/50
8/9+17/18-6/27=8×17, 9×18-6/27=136/162-6/27=136×1, 27×27=136/729
Sper ca înțelegi!
