Bài 1: 2/31/3.(-2/35/6):2/3 Bài 2: a) -2/5(-5/92/5) b) 17/13 (4/13-11) c) 3/5.18/173/5.9/17-3/5.10/17 Bài 3: a) 3/4:x

Question

Bài 1:
2/3+1/3.(-2/3+5/6):2/3
Bài 2:
a) -2/5+(-5/9+2/5)
b) 17/13 (4/13-11)
c) 3/5.18/17+3/5.9/17-3/5.10/17
Bài 3:
a) 3/4:x=5/12
b) x-1/2= 3/4:3/2
c) 1 1/2.x-1/2= 3/4
Ai làm xong trước mik sẽ cho ctlhn ạ
Làm bao nhiêu câu cũng đc ko bắt làm hết

thanhbinh2k5 · Answer

Giải      B&agrave;i 1 :          2/3 + 1/3.(-2/3 + 5/6 ) : 2/3      = 2/3 + 1/3. 1/6 : 2/3     =  2/3 + 1/18 . 3/2     = 2/3 + 1/12     = 8/12 + 1/12     = 3/4       B&agrave;i 2 :       a ) -2/5 + (-5/9 + 2/5 )        = -2/5 - 5/9 + 2/5       = ( -2/5 + 2/5 ) - 5/9       =      0              - 5/9       = -5/9      b ) 17/13 - ( 4/13 -11 )        = 17/13 - ( -139/13 )        = 12      c ) 3/5 . 18/17 + 3/5 . 9/17 - 3/5 . 10/17        = 3/5 . ( 18/17 + 9/17 - 10/17 )        = 3/5 . 1       = 3/5      B&agrave;i 3 :       a ) 3/4 : x = 5/12                   x = 3/4 : 5/12                   x = 9/5     b ) x - 1/2 = 3/4 : 3/2           x - 1/2 = 3/4 . 2/3          x - 1/2 = 1/2           x          = 1/2 + 1/2           x          = 2/2 = 1

quynhthanhnhu · Answer

B&agrave;i 1:       2/3+1/3&times;(-2/3+5/6):2/3     =2/3+1/3&times;(-4/6+5/6)&times;3/2     =2/3+1/3&times;1/6&times;3/2     =2/3+1/12     =8/12+1/12     =9/12=3/4     ---------------------------------------     B&agrave;i 2:     a) -2/5+(-5/9+2/5)     =-2/5+(-25/45+18/45)     =-2/5+(-7/45)     =-18/45+(-7/45)     =-25/45=-5/9     ------------------------------------     b) 17/13-(4/13-11)     =17/13-(4/13-143/13)     =17/13-(-139/13)     =156/13=12     --------------------------------------     c) 3/5.18/17+3/5.9/17-3/5.10/17     = 3/5&times;(18/17+9/17-10/17)     = 3/5&times;17/17     =3/5&times;1     =3/5     ----------------------------------------     B&agrave;i 3:     a) 3/4:x=5/12               x=3/4:5/12               x=9/5     &rArr;x=9/5     -------------------------------------     b) x-1/2= 3/4:3/2     x-1/2=1/2     x=1/2+1/2     x=1     &rArr;x=1     ----------------------------------------     c) 1 1/2.x-1/2= 3/4     3/2x-1/2=3/4     3/2x=3/4+1/2     3/2x=5/4     x=5/4:3/2     x=5/6     &rArr;x=5/6

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