24/32

24/32

a) -12,13; -2,4; -2,3; 0,5; 2,4

b) 2,999; 2,9; -2,9; -2,999

a) -12,13; -2,4; -2,3; 0,5; 2,4

b) 2,999; 2,9; -2,9; -2,999

a) -12,13; -2,4; -2,3; 0,5; 2,4

b) 2,999; 2,9; -2,9; -2,999

Sắp xếp theo thứ tự từ bé đến lớn 

9/5;1/6;15/7

a) Thứ tự tăng dần: 1, 23; 1,234; 12,3; 12,34; 13,4; 123,4

b) Thứ tự giảm dần: 2,1; 1,2; 1,12; 1,1; 0,12; 0,1; 0,01 

a) xếp đúng : 1,23; 1,234; 12,3; 12,34; 13,4; 123,4

b) xếp đúng : 2,1; 1,12; 1,2; 1,1; 0,12; 0,1; 0,01

Ta có: \(\frac{-3}{5}=\frac{-3\cdot16}{5\cdot16}=\frac{-48}{80};\frac{4}{-8}=\frac{-4}{8}=\frac{-4\cdot10}{8\cdot10}=\frac{-40}{80}\)

\(\frac54=\frac{5\cdot20}{4\cdot20}=\frac{100}{80};\frac{3}{-10}=\frac{-3}{10}=\frac{-3\cdot8}{10\cdot8}=-\frac{24}{80}\) ;

\(\frac{-12}{30}=\frac{-12:6}{30:6}=\frac{-2}{5}=\frac{-2\cdot16}{5\cdot16}=\frac{-32}{80}\)

\(\frac32=\frac{3\cdot40}{2\cdot40}=\frac{120}{80}\)

mà \(-\frac{48}{80}<-\frac{40}{80}<-\frac{32}{80}<-\frac{24}{80}<\frac{100}{80}<\frac{120}{80}\)

nên \(-\frac35<-\frac12<-\frac25<\frac{3}{-10}<\frac54<\frac32\)

lớn hơn 1

Mà (vì 6 > 3) và (3 < 5)

nên ta có kết luận là:

Ta có: \(-\frac{12}{7}<\frac{-7}{7}=-1\)

\(-1=\frac{-40}{40}<\frac{-35}{40}<\frac{-24}{40}\)

=>\(-1<-\frac78<-\frac35\)

Do đó: \(-\frac{12}{7}<-1<-\frac78<-\frac35<0\) (1)

Ta có: \(\frac25=\frac{2\cdot6}{5\cdot6}=\frac{12}{30};\frac{13}{5}=\frac{13\cdot6}{5\cdot6}=\frac{78}{30}\)

\(\frac{7}{15}=\frac{7\cdot2}{15\cdot2}=\frac{14}{30};1=\frac{1\cdot30}{30}=\frac{30}{30};\frac92=\frac{9\cdot15}{2\cdot15}=\frac{135}{30}\)

mà \(\frac{12}{30}<\frac{14}{30}<\frac{30}{30}<\frac{78}{30}<\frac{135}{30}\)

nên \(0<\frac25<\frac{7}{15}<1<\frac{13}{5}<\frac92\) (2)

Từ (1),(2) suy ra \(-\frac{12}{7}<-1<-\frac78<-\frac35<0<\frac25<\frac{7}{15}<1<\frac{13}{5}<\frac92\)

\(\dfrac{-12}{7};-1;\dfrac{-7}{8};\dfrac{3}{-5};0;\dfrac{2}{5};\dfrac{-7}{-15};1;\dfrac{-13}{-5};\dfrac{9}{2}\)