7/9 : ( 2 + 3/4 x) + 5/9 = 23/27
7/9 : ( 2 + 3/4 x) = 23/27 - 5/9 = 8/27
2 + 3/4 x= 7/9 : 8/27 = 21/8
3/4x = 21/8 - 2 = 5/8
=> x = 5/8 : 3/4 = 5/6
=)7/9:(2+3/4x)=8/27
=)2+3/4x=21/8
=)3/4x=5/8
=)x=5/6
7/9:(2+3/4x)+5/9=23/27
b) x−15−[(27+x)−(x−13)]=−1
Bài 3. Tìm số nguyên x , biết: a) 43+(9−21)=317−(x−317)
b) (15−x)+(x−12)=7−(−5+x)
a) 2/5 + 3/5 . ( 3x - 3,7 ) = -53/10
b) 7/9 : ( 2 + 3/4x ) + 5/9 = 23/27
Câu 4 : Tìm x , biết :
a, | x + 9 | . 4 - 2 = 10
b, 4x + 12 = 3 ( x - 7 )
c, ( x + 2 015 ) ( x - 2 016 ) = 0
2/3x-3/2x=5/12
b)2/5+3/5.(3x-3,7)=-53/10
c)7/9:(2+3/4x)+5/9=23/27
Tìm x biết:
2/5 + 3/5.(3x - 3,7) = -53/10
7/9 : (2+3/4x)+ 5/9 = 23/27
-2/3 . x + 1/5 = 3/10
|x| - 3/4 = 5/3
|2x- 1/3| + 5/6 = 1
\(7/9:(2+3/4x)+5/9=23/27\)
Giúp mk nha ....
Mk c.ơn
B1.Tìm A/B biết:
A=4/(7*31)+6/(7*41)+9/(10*41)+7/(10*57)
B=7/(19*31)+5/(19*43)+3/(23*43)+11/(23*57)
B2:CMR:
A=1/52+2/53+3/54+...+11/512 <1/16
Tính nhanh: LƯU Ý tất cả số dưới đây đều là phân số
1,1/8 x 2/5 + 3/5 + 1/8
2,( -1)/15 x 2/5 + (-5)/3 x (-1)/13
3,4/9 : 11/6 + 5/9 x 6/11
4,5/19 x 7/13 + 7/19 x 8/13 - 3 x 7/19
5, 2/7 x 4/23 - 2/7 x 27/23 + 2/7
6,3/8 x 3/7 +3/8 x 4/7 + 11/8
7,-5/27 : 6/11 - 16/11 x 5/27 - 5/27
8, 5/16 x 7/8 - 5/16 x 1/8 + 10/8 :16/5
9,1/3 x 39/17 - 129/3 x 1/17
10,5/2 : 23/3 - 3/2 x 7/23
