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\(\frac{36}{45}=\frac{4}{5};\frac{42}{45}=\frac{14}{15}\)
Có: \(\frac{4}{5}=\frac{12}{15}<\frac{14}{15}\Rightarrow\frac{36}{45}<\frac{42}{45}\)
![](https://rs.olm.vn/images/avt/0.png?1311)
rút gọn phân số :
4/5+21/15=4/5+7/5=11/5
8/9-25/45=8/9-5/9=3/9
tính :
5/6+2/7+15/6=5/6+15/6+2/7
=10/3+2/7=76/21
7/8-9/6.7/8=7/8-21/16=-7/16
chúc bạn học tốt !!!
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a)
* Rút gọn : 21/56 = 3/8 ; 60/96 = 5/8
Vì 3 < 5
=> 3/8 < 5/8 ( hay 21/56 < 60/96 )
Vậy 21/56 < 60/96
![](https://rs.olm.vn/images/avt/0.png?1311)
\(\text{a)}\)
\(\text{Ta có: }\text{ }\frac{21}{56}=\frac{21:7}{56:7}=\frac{3}{8}\text{ và }\frac{60}{96}=\frac{60:12}{96:12}=\frac{5}{8}\)
\(\Rightarrow\frac{21}{56}< \frac{60}{96}\left(\frac{3}{8}< \frac{5}{8}\right)\)
\(\text{b)}\)
\(\text{Ta có: }\frac{75}{100}=\frac{75:25}{100:25}=\frac{3}{4}\text{ và }\frac{45}{36}=\frac{45:9}{36:9}=\frac{5}{4}\)
\(\Rightarrow\frac{75}{100}< \frac{45}{36}\left(\frac{3}{4}< \frac{5}{4}\right)\)
\(\text{# học tốt #}\)
![](https://rs.olm.vn/images/avt/0.png?1311)
a) 2/5+9/5=11/5
b) 15/45+25/30=7/6
c) 28/32+45/72=3/2
d) 8/28+5/30=19/42
bài 2
a) x - 4/5 =4/5 + (3/7+3/5)
x-4/5=4/5+36/35
x-4/5=64/35
x=64/35+4/5
x=92/35
b) x-7/35=4/5
x=4/5+7/35
x=1
nhớ tk m nhé
a = 18/5
b = 3/9 + 5/6 = 6/18 + 25/18 = 31/18
c = 7/8 + 5/8 = 12/8
d = 4/14 + 1/6 = 14/42 + 7/42 = 21/42 -= 7/14
b2
x - 4/5 = 4.5 + ( 3/7 + 3/5 )
x - 4/5 = 49/35
x = 49/35 + 4/5
x = 77/35
x - 7/35 = 4/5
x = 4/5 + 7/35
x = 1
mình ko chắc chắn đâu
mình nghĩ mình làm sai
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\(\frac{12}{84}+\frac{36}{63}\)
\(=\frac{1}{7}+\frac{4}{7}=\frac{5}{7}\)
học tốt ~~~
\(\frac{12}{84}=\frac{1}{4}\)
\(\frac{36}{63}=\frac{4}{7}\)
Ta có :
\(\frac{1}{4}=1-\frac{3}{4}\)
\(\frac{4}{7}=1-\frac{3}{7}\)
Mà \(\frac{3}{4}>\frac{3}{7}\) nên \(\frac{1}{4}< \frac{4}{7}\)
\(\Rightarrow\) \(\frac{12}{84}< \frac{36}{63}\) .
![](https://rs.olm.vn/images/avt/0.png?1311)
15/45 + 25/30 = 1/3 + 5/6 = 2/6 + 5/6 = 7/6
28/32 + 45/72 = 7/8 + 5/8 = 12/8 rút gọn là 3/2
8/28 + 5/30 = 2/7 + 1/6 = 12/42 + 7/42 = 19/42
Tik nhaaaaa
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`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
70/970/9 ( tối giản)
96/72=(96:24)/972:24)=4/396/72=(96:24)/972:24)=4/3
45/35=(45:5)/(35:5)=9/745/35=(45:5)/(35:5)=9/7
24/36=(24:12)/(36:12)=2/324/36=(24:12)/(36:12)=2/3
25/100=(25:25)/(100:25)=1/425/100=(25:25)/(100:25)=1/4
![](https://rs.olm.vn/images/avt/0.png?1311)
a) 8/12 + 9/27 x 4/7
= 2/3 + 1/3 x 4/7
= 2/3 + 4/21
= 18/21
= 6/7
b) 8/16 x 36/45 - 4/25
= 1/2 x 4/5 - 4/25
= 2/5 - 4/25
= 6/25
\(\frac{8}{36}\text{x}\frac{45}{70}=\frac{8:4}{36:4}\text{x}\frac{45:5}{70:5}\)
\(=\frac{2}{9}\text{x}\frac{9}{14}=\frac{2\text{x}9}{9\text{x}2\text{x}7}\)
\(=\frac{1}{7}\)
thank