![](https://rs.olm.vn/images/avt/0.png?1311)
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
1 /x+3/=-21+7
/x+3/=-14
xét 2 trường hợp x+3=14 hoac x+3=-14
cai x+3=14 tu lam
x+3=-14 nhu ben tren dinh ay
![](https://rs.olm.vn/images/avt/0.png?1311)
a. 3/7 - 1/2x = 5/3
=> 1/2x = 3/7 - 5/3
=> 1/2x = 9/21 - 15/21
=> 1/2x = -26/21
=> x = -26/21 : 1/2
=> x = -26/21.2
=> x = -52/21
b. -2x + 3/14 = 1/7 - 4/21
=> -2x = -3/14 + 1/7 - 4/21
=> -2x = -18/84 + 12/84 - 16/84
=> -2x = -22/84
=> x = -22/84 : -2
=> x = -22/84 . (-1/2)
=> x = 11/84
a. 3/7 - 1/2x = 5/3
=> 1/2x = 3/7 - 5/3
=> 1/2x = 9/21 - 15/21
=> 1/2x = -26/21
=> x = -26/21 : 1/2
=> x = -26/21.2
=> x = -52/21
b. -2x + 3/14 = 1/7 - 4/21
=> -2x = -3/14 + 1/7 - 4/21
=> -2x = -18/84 + 12/84 - 16/84
=> -2x = -22/84
=> x = -22/84 : -2
=> x = -22/84 . (-1/2)
=> x = 11/84
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
Lời giải:
a.
$x=\frac{7}{25}+\frac{-1}{5}=\frac{7}{25}+\frac{-5}{25}=\frac{7-5}{25}=\frac{2}{25}$
b.
$x=\frac{5}{11}+\frac{4}{-9}=\frac{5}{11}-\frac{4}{9}=\frac{45}{99}-\frac{44}{99}=\frac{1}{99}$
c.
$\frac{x}{-1}=\frac{-1}{3}-\frac{5}{9}=\frac{-3}{9}-\frac{5}{9}=\frac{-8}{9}$
$x=(-1).\frac{-8}{9}=\frac{8}{9}$
![](https://rs.olm.vn/images/avt/0.png?1311)
làm mẫu nhé:
a) /4/5 - 1/5x/ - 2/3 = 1/5
=> /4/5 - 1/5x/ = 1/5 + 2/3 = 13/15
=> /4/5 - 1/5x/ = 13/15
/ 4/5 - 1/5x / = -13/15
=> 1/5x = 4/5 - 13/15 = -1/15 => x = -1/15 : 1/5 = -1/3
=> 1/5x = 4/5 - (-13/15) = 5/3 => x = 5/3 : 1/5 = 25/3
còn lại tương tự nha
![](https://rs.olm.vn/images/avt/0.png?1311)
Bài 1:
a) =25,97+(6,54+103,46)
=25,97+110
=135,97
b)136x75+75x64
=75x(136+64)
=75x200
=15 000
c) (21/8+1/2):5/16
=(21/8+4/8)x16/5
=25/8x16/5
=10
d)3/17-4/5+14/17
=(3/17+14/17)-4/5
=1-4/5
=1/5
Bài 2:
a)720:\([41-(2x-5)]\)=120
41 - (2x-5) =720:120
41 - (2x-5) =6
2x-5 =41-6
2x-5 =35
2x =35+5
2x =40
x =40:2
x =20
b)2/3 x X +3/4=3
2/3 x X =3-3/4
2/3 x X =12/4-3/4
2/3 x X =9/4
x =9/4:2/3
x =9/4x3/2
x =27/8
c) x+0,34=1,19x1,02
x+0,34=1,2138
x =1,2138-0,34
x =0,8738
\(a.\dfrac{1}{4}+\dfrac{3}{4}x=-0,3\)
\(\Leftrightarrow\dfrac{3}{4}x=-\dfrac{11}{20}\)
\(\Leftrightarrow x=-\dfrac{11}{15}\)
\(b.\dfrac{4}{7}x-\dfrac{7}{3}=\dfrac{1}{21}\)
\(\Leftrightarrow\dfrac{4}{7}x=\dfrac{50}{21}\)
\(\Leftrightarrow x=\dfrac{25}{6}\)