1,tính a, 9/17.3/7+9/17:7/4 b, 6/7.8/13+6/13.9/7-4/13.6/7 2, tìm x a,3/4.x=1/2 b,4/5+5/7:x=1/6

2 bình luận về “1,tính a, 9/17.3/7+9/17:7/4 b, 6/7.8/13+6/13.9/7-4/13.6/7 2, tìm x a,3/4.x=1/2 b,4/5+5/7:x=1/6”

1. Giải đáp:

   1.

   a) 9/17 . 3/7 + 9/17 : 7/4

   = 9/17 . 3/7 + 9/17 . 4/7

   = 9/17 .(3/7+4/7)

   = 9/17 .1

   = 9/17

   b) 6/7 . 8/13 + 6/13 . 9/7 – 4/13 . 6/7

   = 6/7 . 8/13 + 6/7 . 9/13 – 4/13 . 6/7

   = 6/7 . (8/13 + 9/13 – 4/13)

   = 6/7 .1

   = 6/7

   $\\$

   2.

   a) 3/4 . x=1/2

   =>x=1/2 : 3/4

   => x=1/2 . 4/3

   => x=2/3

   Vậy x=2/3

   b) 4/5 + 5/7 : x=1/6

   => 5/7 :x=1/6 – 4/5

   => 5/7 :x=(-19)/30

   => x=5/7 : (-19)/30

   => x=(-150)/133

    

   Trả lời
2. Bài 1 :

   a, 9/17 * 3/7 + 9/17 : 7/4

   = 9/17 * 3/7 + 9/17 * 4/7

   = 9/17 * ( 3/7 + 4/7 )

   = 9/17 * 1

   = 9/17

   —

   b, 6/7 * 8/13 + 6/13 * 9/7 – 4/13 * 6/7

   = 6/7 * 8/13 + 6/7 * 9/13 – 4/13 * 6/7

   = 6/7 * ( 8/13 + 9/13 – 4/13)

   = 6/7 * 1

   = 6/7

   —–

   Bài 2 :

   a, 3/4 x= 1/2

   x = 1/2 : 3/4

   x = 2/3

   Vậy x= 2/3

   —

   b, 4/5 + 5/7 : x = 1/6

   5/7 : x = 1/6 – 4/5

   5/7 : x= -19/30

   x = 5/7 : (-19)/30

   x = -150/133

   Vậy x = -150/133

    

   Trả lời