9. rút gọn các phân số sau

\(\dfrac{24}{32}=\dfrac{3}{4};\dfrac{14}{35}=\dfrac{2}{7};\dfrac{30}{25}=\dfrac{6}{5};\dfrac{63}{36}=\dfrac{7}{3}\)

A) 

24/32=3/4

14/35=2/5

30/25=6/5

63/36=7/4

B)

3/5 và 4/7=21/35 và 20/35

2/3 và 5/6=4/6 và 5/6

4/9 và 1/6=8/18 và 3/18

a,3/4; 2/5; 6/5 7/4;

b: \(=\dfrac{3}{7}\cdot\dfrac{5}{7}\cdot\dfrac{6}{7}=\dfrac{90}{343}\)

c: \(=\dfrac{4}{9}\cdot\dfrac{5}{9}\cdot\dfrac{3}{7}=\dfrac{20}{189}\)

d: \(=\dfrac{1}{3}\cdot\dfrac{5}{12}\cdot\dfrac{5}{12}=\dfrac{25}{432}\)

d

a; \(\dfrac{9}{27}\) + \(\dfrac{7}{-49}\)

= \(\dfrac{1}{3}\) - \(\dfrac{1}{7}\)

= \(\dfrac{7}{21}\) - \(\dfrac{3}{21}\)

= \(\dfrac{4}{21}\)

b; - \(\dfrac{12}{10}\) + \(\dfrac{-25}{30}\)

   =  - \(\dfrac{6}{5}\) - \(\dfrac{5}{6}\)

   = -\(\dfrac{36}{30}\) - \(\dfrac{25}{30}\)

  = \(\dfrac{-61}{30}\) 

c; \(\dfrac{-20}{35}\) + \(\dfrac{-16}{-24}\)

 =  - \(\dfrac{4}{7}\) + \(\dfrac{2}{3}\)

= - \(\dfrac{12}{21}\) + \(\dfrac{14}{21}\)

=  \(\dfrac{2}{21}\)

d; - \(\dfrac{21}{77}\) + \(\dfrac{10}{-35}\)

 = - \(\dfrac{3}{11}\) - \(\dfrac{2}{7}\)

 = - \(\dfrac{21}{77}\) -  \(\dfrac{22}{77}\)

= - \(\dfrac{43}{77}\)

33/15 x 35/21 x 63/14 x 9/30

= 11/5 x 5/3 x 9/2 x 3/10

= 99/20

= \(\frac{33}{15}\)x \(\frac{5}{3}\)x \(\frac{9}{2}\)x \(\frac{3}{10}\)

= \(\frac{11}{3}\)x \(\frac{9}{2}\)x \(\frac{3}{10}\)

= \(\frac{33}{2}\)x \(\frac{3}{10}\)

= \(\frac{99}{20}\)

a=(35+45):2=40

b=(37+42+56):3=45

c=(20+32+24+36):4=28

d=(25+37+30+15+63):5=34

kết quả bằng 765

11 + 12 + 13 + ... + 40

số số hạng : ( 40 - 11 ) : 1 + 1 = 30

tổng : ( 40 + 11 ) x 30 : 2 = 765

đáp số : 765

`6/10=3/5`

`70/9=70/9`

`96/72=4/3`

`45/35=9/7`

`24/36=2/3`

`25/100=1/4`

$6/10=(6:2)/(10:2)=3/5$

$70/9$ ( tối giản)

$96/72=(96:24)/972:24)=4/3$

$45/35=(45:5)/(35:5)=9/7$

$24/36=(24:12)/(36:12)=2/3$

$25/100=(25:25)/(100:25)=1/4$