Toán Lớp 7: Tìm x c) | 3-x| = 1/12 d) | x-2| + 1 = 6/4

Question

Toán Lớp 7:  Tìm x c) | 3-x| = 1/12 d) | x-2| + 1 = 6/4

tuanh · Answer

c) | 3 - x | = 1/12   => [ 3 - x =  1/12         [ 3 - x =  - 1/12   => [ x = 3 - 1/12         [ x = 3 - ( - 1/12 )   => [ x = 36/12 - 1/12         [ x = 36/12 - ( - 1/12 )   => [ x = 35/12         [ x = 37/12   Vậy x = { 35/12 ; 37/12 }   d)  | x - 2 | + 1 = 6/4         | x - 2 |  = 6/4 - 1        | x - 2 | = 6/4 - 4/4       | x - 2 | = 1/2   =>[ x - 2 = 1/2        [ x - 2 = - 1/2   =>[ x = 1/2 + 2        [ x = - 1/2 + 2   =>[ x = 1/2 + 4/2        [ x = - 1/2 + 4/2   =>[ x = 5/2        [ x = 3/2   vậy x = { 5/2 , 3/2 }

chauhoangmy98 · Answer

c)   |3 - x| = 1/(12)     =>   ( left[  begin{array}{l}3-x= frac{1}{12}  3-x=- frac{1}{12} end{array}  right. )     =>   ( left[  begin{array}{l}x= frac{35}{12}  x= frac{37}{12} end{array}  right. )    Vậy x = (35)/2  hoặc  x = (37)/2     d)   |x - 2| + 1 = 6/4     => |x - 2| = 3/2 - 1     => |x - 2| = 1/2     =>   ( left[  begin{array}{l}x-2= frac{1}{2}  x-2=- frac{1}{2} end{array}  right. )     =>   ( left[  begin{array}{l}x= frac{5}{2}  x= frac{3}{2} end{array}  right. )    Vậy  x = 5/2  hoặc  x = 3/2