31 - [ 26- ( 209 + 35 ) ]
\(Tính nhanh : 1 - 6/23 + 6/31 - 6/154 _________________________________ 5/2 - 15/23 - 15/31- 15 /154 \)
1\3+1\31 + 1\1\35 +1\37 + 1\47 + 1\53 + 1\61< 1\2
CMR: 1/3 + 1/31 + 1/35 + 1/37 + 1/47 + 1/53 + 1/61<1/2
A, 31/25 + ( 15/16 - 6/15 ) + 1/16
Tính:
a) 85.(35 - 27) - 35.(85 -27)
b) 47. (45 - 15) - 47.(45+15)
Thực hiện phép tính
a) 23 . 17 - 23 . 14
b) 80 - ( 4 . 5 - 3 . 23 )
c) 35 - { 12 - [ -14 + ( -2) }
d) 49 - ( -45) - 23
e) 13 - 18 - ( -42) - 15
g) -452 - ( -67 + 75 - 452 )
h) \(\left|31-17\right|-\left|13-52\right|\)
x - 15 - 19 =31
Tính
31/25 + ( 15/16 - 6/15 ) +1/16