你到底是三道題還是四道題呢?究竟有什么不懂啊?
37.5 +(28又5/7)+ [(-46又1/2)+ (-25又1/7)]
= 37.5 +28 +5/7 -46.5 -25 -1/7
= -(46.5-37.5) +(28-25) +(5-1)/7
= -9 +3 +4/7
= -6 +4/7
= -5又3/7
(-2又3/5)+ (-1/4)+ (-3又2/5)+ (+2又3/4)+ (-1又1/2)+ (+1又1/3)
= -2 -3/5 -1/4 -3 -2/5 +2 +3/4 -1 -1/2 +1 +1/3
= -2 -3 +2 -1 +1 -3/5 -2/5 -1/4 +3/4 -1/2 +1/3
= -3 -5/5 +2/4 -1/2 +1/3
= -3 +1/2 -1/2 -1 +1/3
= -3 -2/3
= -3又2/3
(1又1/4)+ (-6.5)+ (3又3/8)+ (-1.25)+ (2又5/8)
= 1 +1/4 -6.5 +3 +3/8 -1.25 +2 +5/8
= 1 +3 +2 -6.5 -1.25 +1/4 +3/8 +5/8
= 6 -6.5 -1.25 +1.25 +1
= -0.5 +1
= 0.5
(5/2)*(3/7)- (-3/7)*(11/2)- (-1/2)*(3/7)
=(3/7)*[5+ 11 +1]/2
=(3/7)*17/2
= 51/14