Tìm x :
2 / 7 : x = 8 / 21
Tìm X:
X : 3/9 = 7/8
( X - 21 x 13 ) : 11 = 30
6/16:3/6 < x < 20/21 : 4/21
8/21 x 7 /2 < x < 11/8 x 4
6/16:3/6 < x < 20/21 : 4/21
8/21 x 7 /2 < x < 11/8 x 4
a)3/2 x 4/7 8/21 : 2/3 8/21 : 4/7 4/7 x 2/3
b)3/11 x 2 6/11 : 3/11 6/11 : 2 2 x 3/11
c)4 x 2/7 8/7 : 2/7 8/7 : 4 2/7 x 4
Tìm X
a) 136 – X = 400:8+7
b) x+x+x+15=21
c) 35+X+27=80
Bài 3 : Tính
a) 11/7 + 3/5 , 4 + 1/9 b) 21/5 - 5/8 , 2 - 11/15
c) 3/19 x 38/9 , 21/5 x 2 c) 7/3 : 4/9 , 12/7 : 3
11/15 + 8/15= Tính phân số
6/7 - 5/21=
25/4 x 16/100
7 x 2/49 =
4/3 : 2/9
5/8 : 25 =