Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
quy đồng các phân số sao cho chúng cùng mẫu là so sánh được
Ta có:
a)18/91=18:91=0,197802197
23/114=23:114=0,201754386
Mà:0,197802197<0,201754386 nên 18/91<23/114
b)21/52=21:52=0,403846153
213/523=213:523=0,407265774
Mà:0,403846153<0,407265774 nên 21/52<213/523
c)1313/9191=1313:9191=0,142857142
1111/7373=1111:7373=0,150684931
Mà:0,142857142<0,150684931 nên 1313/9191<1111/7373
^^^^!~~~
a) Ta có :
\(\frac{18}{91}< \frac{18}{90}=\frac{1}{5}=\frac{23}{115}< \frac{23}{114}\)
\(\Rightarrow\frac{18}{91}< \frac{23}{114}\)
b) Ta có :
\(\frac{21}{52}=\frac{210}{520}=1-\frac{310}{520}\)
\(\frac{213}{523}=1-\frac{310}{523}\)
Mà \(1-\frac{310}{520}< 1-\frac{310}{523}\)
\(\Rightarrow\frac{21}{52}< \frac{213}{523}\)
c) Ta có : \(\frac{1313}{9191}=\frac{13}{91}=\frac{1}{7}=\frac{11}{77};\frac{1111}{7373}=\frac{11}{73}\)
Mà \(\frac{11}{77}< \frac{11}{73}\)nên \(\frac{1313}{9191}< \frac{1111}{7373}\)
d) Ta có :
\(\frac{n}{n+1}=\frac{n+1-1}{n+1}=1-\frac{1}{n+1}\)
\(\frac{n+2}{n+3}=\frac{n+3-1}{n+3}=1-\frac{1}{n+3}\)
Mà \(1-\frac{1}{n+1}< 1-\frac{1}{n+3}\)nên \(\frac{n}{n+1}< \frac{n+2}{n+3}\)
a) Ta có : \(\frac{18}{91}< \frac{18}{90}=\frac{1}{5}< \frac{23}{115}< \frac{23}{114}\)
\(\Rightarrow\) \(\frac{18}{91}< \frac{23}{114}\)
Vậy \(\frac{18}{91}< \frac{23}{114}\)
b) Ta có : \(\frac{21}{52}< \frac{21}{56}=\frac{3}{8}< \frac{213}{568}< \frac{213}{523}\)
\(\Rightarrow\) \(\frac{21}{52}< \frac{213}{523}\)
Vậy \(\frac{21}{52}< \frac{213}{523}\)
c) Ta có : \(\frac{1313}{9191}=\frac{1313:1313}{9191:1313}=\frac{1}{7}\)
\(\frac{1111}{7373}=\frac{1111:101}{7373:101}=\frac{11}{73}\)
Lại có : \(\frac{1}{7}< \frac{11}{77}< \frac{11}{73}\)
\(\Rightarrow\) \(\frac{1313}{9191}< \frac{1111}{7373}\)
Vậy \(\frac{1313}{9191}< \frac{1111}{7373}\)
d) Ta có : \(1-\frac{n}{n+1}=\frac{n+1}{n+1}-\frac{n}{n+1}=\frac{1}{n+1}\)
\(1-\frac{n+2}{n+3}=\frac{n+3}{n+3}-\frac{n+2}{n+3}=\frac{1}{n+3}\)
Vì \(n+1< n+3\)
\(\Rightarrow\)\(\frac{1}{n+1}>\frac{1}{n+3}\)
\(\Rightarrow\) \(\frac{n}{n+1}< \frac{n+2}{n+3}\)
Vậy \(\frac{n}{n+1}< \frac{n+2}{n+3}\)
Chúc m.n hok tốt ♡❤️
\(\frac{1313}{9191}=\frac{1313:1313}{9191:1313}=\frac{1}{7}=\frac{73}{511}\)
\(\frac{1111}{7373}=\frac{1111:101}{7373:101}=\frac{11}{73}=\frac{77}{511}\)
Vì \(\frac{73}{511}< \frac{77}{511}\) nên \(\frac{1313}{9191}< \frac{1111}{7373}\).
\(\frac{1313}{9191}=\frac{13}{91}=\frac{1}{7}=0.14...\)
\(\frac{1111}{7373}=\frac{11}{73}=0,15.....\)
MÀ 0, 14 <0, 15
=> \(\frac{1313}{9191}< \frac{1111}{7373}\)
b)
ta có : \(\frac{1313}{9191}=\frac{13}{91}=\frac{1}{7}\)
\(\frac{1111}{7373}=\frac{11}{73}>\frac{11}{77}\)
Mà \(\frac{11}{77}=\frac{1}{7}\)
\(\Rightarrow\frac{11}{73}>\frac{1}{7}\)
Vậy \(\frac{1313}{9191}< \frac{1111}{7373}\)
1-21/52=31/52 1-213/523=310/523 ta có 31/52=310/520
vì 310/520<310/523 nên 21/52 < 213/523
phần còn lại như bạn bên trên nha! chọn mk nhé!
a)\(\frac{18}{91}\)< \(\frac{23}{114}\) ; b) \(\frac{1313}{9191}\) < \(\frac{1111}{7373}\)
a)\(\frac{18}{91}\)\(< \)\(\frac{23}{114}\)
b)\(\frac{1313}{9191}\)\(< \)\(\frac{1111}{7373}\)