1-7-8=-14
muốn kết bạn thì mik còn lượt đó
đúng bấm 
1-7-8=-14
dễ thế mà cũng hỏi
1/tính nhanh
a/\(A=\frac{7}{8}:\left(\frac{2}{9}-\frac{1}{18}\right)+\frac{7}{8}:\left(\frac{1}{36}-\frac{5}{12}\right)\)
b/\(B=\frac{1+0,6-\frac{3}{7}}{\frac{8}{3}+\frac{8}{5}-\frac{8}{7}}-\frac{\frac{1}{3}+0,25-\frac{1}{5}+0,125}{\frac{7}{6}+\frac{7}{8}-0,7+\frac{7}{16}}\)
-7/8-1/4+1/3x(-7/8)-1/2x7/8
a.1/7.-3/8+-13/8
b.3/5.13/40-1/10.16/23
c.(-3/4+2/5):3/7+(3/5+1/4):3/7
d.7/8:(2/9-1/8)+7/8:(1/6-5/12)
e.(-2/3+3/7):4/5+(-1/3+4/7):4/5
Giúp mình với..
lam ho 1)A) 1- (5va4/9 +X -7va 7/18): 15va3/4=0
; B)X +1/2+1/4+1/8+1/16+1/32+1/64+1/128
---------------------------------------------------------- =9/2
1/3*4+1/4*5+1/5*6+1/6*7+1/7*8+1/8*9
2)
a)A=
5+8/17 +8/37
------------------
4+4/17+4/37
B)B=7/12+7/6+7/12+...+7/9900
1) 1/2x + 3/4x = 4/5
2) 3/7 . 5/8 - 3/8 . 13/8 + 1/7
7/8:(2/7-1/18)+7/8/(1/36-5/12)
Bài 1 :Tính nhanh
A=2/7+-3/8+11/7+1/3+1/7+5/-8
B=-3/8+12/25+5/-8+2/-5+13/25
Bài 1 :Tính nhanh
A=2/7+-3/8+11/7+1/3+1/7+5/-8
B=-3/8+12/25+5/-8+2/-5+13/25
\(A=1*2*3*4*5*6*7*8*9-1*2*3*4*5*6*7*8-1*2*3*4*5*6*7*8*8\)
Tính nhanh
a) 31/23 - (7/32 + 8/23)
b) 38/45 - (8/45 - 17/51 - 3/11)
c)(1/3 + 12/67 + 13/41) - ( 79/67 - 28/41)
d) 1/5 + -1/6 + 1/7 + -1/8 + 1/9 + 1/8 + -1/7 + 1/6 + -1/5
