-3/5; 13/7; -1/2; -2/1

a)   -3/5

b)   13/7

c)   -1/4

d)   -2/1

Mẫu số chung là 56 nha anh e

CO 6 CAN DAU 'MOI CAN CHUA7PHAN 2 L DAU NGUOITACHIA DEU CHO 7 GIA DINH .MOI GIA ĐINH CO BAO NHIEU LIT

 Ta có: \(\frac{1}{{ - 2}} = \frac{{1.( - 1)}}{{ - 2.( - 1)}} = \frac{{ - 1}}{2}\)

\(\frac{{ - 3}}{{ - 5}} = \frac{{ - 3.( - 1)}}{{ - 5.( - 1)}} = \frac{3}{5}\)

\(\frac{2}{{ - 7}} = \frac{{2.( - 1)}}{{ - 7.( - 1)}} = \frac{{ - 2}}{7}\).

\(\dfrac{1}{-2}=\dfrac{-1}{2}\)

\(\dfrac{-3}{-5}=\dfrac{3}{5}\)

\(\dfrac{2}{-7}=\dfrac{-2}{7}\)

a, \(\frac{4}{7}\): Giữ nguyên

\(2=\frac{14}{7}\)

b, \(3=\frac{12}{4}\)

\(\frac{6}{8}=\frac{3}{4}\)

a) \(\frac{4}{7}\): Giữ nguyên

\(2=\frac{4}{7}\)

b) \(3=\frac{12}{4}\)

\(\frac{6}{8}=\frac{3}{4}\)

Bài 1: 

a: 3/-5=-3/5=-6/10

b: 5/-10=-1/2=-5/10

c: -4/-9=4/9=8/18

d: -6/8=-3/4=-9/12

e: 0/-10=0

f: 0/-6=0

1.

a) \(\frac{3}{-5}=\frac{3:\left(-1\right)}{-5:\left(-1\right)}=\frac{-3}{5}\) b) \(\frac{-13}{-7}=\frac{-13:\left(-1\right)}{-7:\left(-1\right)}=\frac{13}{7}\)

c) \(\frac{-4}{8}=\frac{-4:4}{8:4}=\frac{-1}{2}\) d)\(\frac{-34}{17}=\frac{-34:17}{17:17}=\frac{-2}{1}\)

2.

a)\(\frac{5}{12}va\frac{10}{12}\) b\(\frac{-3}{12}va\frac{1}{-4}\)

\(\frac{5}{12}\ne\frac{10}{12}\) vì 5.12\(\ne\)10.12 \(\frac{-3}{12}=\frac{1}{-4}\)vì -3.(-4)=1.12

c)\(\frac{4}{1}va\frac{-72}{-18}\)

\(\frac{4}{1}=\frac{-72}{-18}\)vì 4.(-18)=1.(-72)

a)-3/5      b)13/7         c)-1/2         d) -2/1

2x/5=24/10

2x =5x24:10

  x=12:2

x=6 

tui giải câu tìm x:

x = 12.

Tuy không đủ nhưng mong mọi người tick