(1)(-8)+(-9); (2)(-17)+21;
(3)(-12)+25; (4)45+(-23); (5)(-45)+23 (6)(-29)+(-31);
(7)(-39)+(-45) (8)(-28)+37; (9)(-13)+0.
[主观题]计算。5/9+(3/4-1/2)1/10+3/8-2/53/5-(2/15+1/3)
[主观题]计算。7/8-5/6=2/9+1/2=6/7-2/3=3/10+1/4=3/7+1/9=1/3-1/5=1/6+1/4=5/7-1/5=
[单选题]1/2,3/2 ,11/8 ,21/32 ,( )A. 7/64B. 25/64C.12/31D. 13/64
[主观题]1/3,3/9,2/3,13/21,()A.17/27;B.17/26;C.19/27;D.19/28;
[单选题]1/3,3/9,2/3,13/21,()A .17/27B .17/26C .19/27D .19/28
[单选题]1, 2, 3,8, 21,46, ( )。A.70B.87C.90D.100
[主观题]填空。2/7=()/219/12=3/()5÷3=()/()=1又()/()
[单选题]1,8,9,17,26,( )。A.126B.59C.43D.37
[单选题]1,0,2,5,3,8,4,17,( ),( )A.6,35B.6,37C.5,24D.5,26
[主观题]计算。1/9+5/9+2/9=6/11+3/11+1/11=1/4+1/4+3/4=7/10-1/10-3/10=11/6-7/6-1/6=1-2/3-1/3=