Toán Lớp 6: Bài 4 Tìm x biết a, 3/4 .x+1=-2 b,(x + 1/4-1/3):(2+1/6-1/4)= 7/46 d,13/15-(13/21+x).7/12=7/10 Làm hộ nhé

Question

Toán Lớp 6:  Bài 4 Tìm x biết a, 3/4 .x+1=-2 b,(x + 1/4-1/3):(2+1/6-1/4)= 7/46 d,13/15-(13/21+x).7/12=7/10 Làm hộ nhé

minhtamnguyet88 · Answer

a) 3/4&times;x+1=-2   3/4&times;x=-2-1   3/4&times;x=-3   x=-3:3/4   x=-3&times;4/3   Vậy x=-4   b) (x+1/4-1/3):(2+1/6-1/4)=7/46   (x+1/4-1/3):(24/12+2/12-3/12)=7/46   (x+1/4-1/3):23/12=7/46   x+1/4-1/3=7/46&times;23/12   x+1/4-1/3=7/36   x+1/4=7/36+1/3   x+1/4=7/36+12/36   x+1/4=19/36   x=19/36-1/36   x=19/36-9/36   x=10/36   Vậy x=5/18    d) 13/15-(13/21+x)&times;7/12=7/10     (13/21+x)&times;7/12=13/15-7/10     (13/21+x)&times;7/12=26/30-21/30     (13/21+x)&times;7/12=1/6     13/21+x=1/6:7/12     13/21+x=1/6&times;12/7     13/21+x=2/7     x=2/7-13/21     x=6/21-13/21     x=-7/21     Vậy x=-1/3

hiennhi98 · Answer

a, 3/4 . x + 1 = -2         3/4 . x       = -2 - 1          3/4 . x       = - 3                  x        = -3 : 3/4                  x        = -4     Vậy x = -4     b, (x + 1/4 - 1/3) : (2 + 1/6 - 1/4) = 7/46         (x + 1/4 - 1/3) : (13/6 - 1/4)      = 7/46         (x + 1/4 - 1/3) : 23/12               = 7/46         (x + 1/14 - 1/3)                         = 7/46 x 23/12          x + 1/4 - 1/3                             = 7/24          x + 1/4                                     = 7/24 + 1/3          x + 1/4                                     = 5/8          x                                               = 5/8 - 1/4          x                                                = 3/8    Vậy x = 3/8   d, 13/15 - (13/21 + x) . 7/12 = 7/10                     (13/21 + x) . 7/12 = 13/15 - 7/10                      (13/21 + x) . 7/12 = 1/6                      13/21 + x              = 1/6 : 7/12                      13/21 + x              = 2/7                                   x               = 2/7 - 13/21                                   x                = -1/3     Vậy x = -1/3