7дробь8-0,4= 0,5-1дробь48=
7/8-0,4=4/10=7/8-4/10=20/40-16/40=4/40=1/10=0,1
7/8=35/40, а не 20/40
да
35/40-16/40=19/40=0,475
7/8-0,4=7/8-4/10=7/8-2/5=35/40-16/40=19/40 0,5-1/48=5/10-1/48=1/2-1/48=14/48-1/48=13/48
7/8-0.4=35/40-16/40=19/40 0,5-1/48=31/58