51-【26.5×0.375-(8.3-7又37/40)+未知数÷2又2/3】=5026.5×0.375-(8.3-7又37/40)+未知数÷2又2/3=126.5×0.375-0.375+未知数÷2又2/3=1（26.5-1）×0.375+未知数÷2又2/3=125.5×0.375+未知数÷2又2/3=19.5626+未...