5 7/8 -(2-1 1/15) : 4/25+5/6
2-1 1/15=14/15 14/15:4/25=14/15*25/4=35/6 5 7/8-35/6=47/8-35/6= 141/24-140/24=1/24 1/24+5/6=1/24+20/24=21/24=7/8