7/4一(3/8十1/10)=51/40
(1)51╱40(2)x-7/4=3-1/2解得x=17/4
7/4-(3/8+1/10)=14/8-3/8-1/10=55/40-4/40=1又11/407/4+3-1/2=4又3/4-2/4=4又1/4