Question

9.Tìm x biết

a)x+1/3=3/4

b)x-2/5=5/4

c)-x-2/3=6/7

d)4/7-x=1/3

 

Answer 1

a, x + 1/3 = 3/4

- > x = 3/4 - 1/3 = 5/12

b, x - 2/5 = 5/4

-> x = 5/4 + 2/5 = 33/20

c, -x - 2/3 = 6/7

-> -x = 6/7 + 2/3 = 32/21

-> x = -32/21

d, 4/7 - x = 1/3

x = 4/7 - 1/3 = 5/21

Answer 2

a) x+1/3= 3/4 

   x= 3/4 - 1/3

   x= 5/12

b) x-2/5 = 5/4 

    x= 5/4 + 2/5 

    x = 33 / 20

c) -x - 2/3 = 6/7 

    -x = 6/7 + 2/3 

    -x = 32/21 => x = -32/21

d) 4/7 -x = 1/3 

    x= 4/7 -1/3

   x = 5/21

Answer 3

a) x + 1/3 = 3/4 

    x         = 3/4 - 1/3

    x         = 5/12

b) x - 2/5 = 5/4

    x        = 5/4 + 2/4

    x        = 7/4

c) (-x) - 2/3 = 6/7

     -x         = 6/7 + 2/3

     -x         = 6/21

      x          = -6/21

d) 4/7 - x = 1/3

           x = 4/7 - 1/3

           x = 5/21

Answer 4

a) x + 1/3 = 3/4

   x          = 3/4 - 1/3

   x          =    5/12

b) x - 2/5 = 5/4 

   x         = 5/4 + 2/5

   x         =      33/13

c) -x - 2/3 = 6/7

   -x         = 6/7 + 2/3

   -x         = 32/21

  \(\Rightarrow x=-\frac{32}{21}\)

d) 4/7 - x = 1/3

           x = 4/7 - 1/3

           x =     5/21