Tính giá trị biểu thức bằng cách hợp lý nhất
(1/5-2/7).3/4-3/4.(1/3-2/7)
B = __________________________
1/5.2/7-1/3.(2/7+3/9)+3/9.1/5
(3-1/4+2/3) - (5-1/3-6/5) - (6-7/4+3/2) (6-2/3+1/2) - (5+5/3-3/2)-(3-7/3+5/2)
(5/3-3/7+9)-(2+5/7-2/3)+(8/7-4/3-10) (8-9/4+2/7)-(-6-3/7+5/4)-(3+2/4-9/7 )
mọi người ơi giúp mik với ạ
1, ( -2/5 + 3/10 ) : ( 2/-5 + |-4/3 - 2| )
2, 12,5 . -5/7 + 9 3/4 - 1,5 . 5/7
3, -1/4 . -5/13 - 5/4 . -7/13 + 1/1,3
4, ( -3/4 + 5/13 ) : 2/7 - ( 2 1/4 + 8/13 ) : 2/7
5, ( 3 - 3/4 + 2/3 ) - ( 2 - 4/3 - 3/2 ) - ( 1 - 7/3 - 9/2 )
6, -1/3 - 8/35 + -2/9 - 1/135 z+ 4/5 + -4/9 + 3/7
5) (3-1/4+2/3) - (5-1/3-6/5) - (6-7/4+3/2) 6) (6-2/3+1/2) - (5+5/3-3/2)-(3-7/3+5/2)
7) (5/3-3/7+9)-(2+5/7-2/3)+(8/7-4/3-10) 8) (8-9/4+2/7)-(-6-3/7+5/4)-(3+2/4-9/7 pls help me
a)8.(-5).(-4).2
b)1 3/7 +(-1/3+2 4/7)
c)8/5.2/3+-5.5/3.5
d)6/7+5/8:5-3/16(-2)2
a)-1/24-[1/4-(1/2-7/8)]
b)(5/7-7/5)-[-1/2-(-2/7-1/10)
c)(-1/2)-(-3/5)+(-1/9)+1/71-(-2/7)+4/35-7/18
d) (3-1/4+2/3) -(5-1/3-6/5)-(6-7/4+3/2)
Tính:
a) -5/7(14/5 - 7/10) : |-2/3| - 3/4(8/9 + 16/3) + 10/3(1/3 + 1/5)
b) 17/-26(1/6 - 5/3) : 17/13 - 20/3(2/5 - 1/4) + 2/3(6/5 - 9/2)
c) -8/9(9/8 - 3/2) + 5/4 : (5/2 - 15/4) - 3/4(10/9 - 8/3) : (-1/3)
d) 21/10 : (12/5 - 9/10) . (-4/7) - 3/2(1/6 - 7/12) + 1/5(3/2 - 1/4)
1. Tính hợp lí:
a) B = 1/2 - [ 3/8 + ( -7/4 ) ]
b) -4/12 - ( -13/39 - 0,25 ) + 0,75
c) 1/2 - 1/3 + 1/23 + 1/6
d) ( -13/7 - 4/9) - ( -10/7 - 4/9 )
e) ( 7/8 - 5/2 + 4/7 ) - ( -3/7 + 1 - 13/8 )
f) -3/7 + ( 3 - 3/4 ) - ( 2,25 - 10/7)
g) ( 5/3 - 3/7 + 9 ) - ( 2 + 5/7 - 2/3 ) + ( 8/7 - 4/3 - 10 )
[-1/2-[-3/5]+[-1/9+1/71-[-2/7]+4/35-7/18
1/3-3/4-[-3/5]+1/64-2/9-1/36+1/15
-5/7-[-5/67]+13/30+1/2+[-11/6]+17/14-[-2/5]
[3-1/4+2/3]-[5-1/3-6/5]-[6-7/4+3/2]
[5+1/5-2/9]-[2-1/23-73/35+5/6]-[8+2/7-1/18]
làm giúp mình mình đang cần gấp