so sanh phan so
201/202+202/205 va 201+202/202+205
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
2/5 x 1/X + 1/X x 2 = 0,1
1/X x ( 2/5 + 2 ) = 0,1
1/X x 12 / 5 = 0,1
1/X = 0,1 :12/5 = 1/10 : 12/5
1/X = 1/24
Vậy X = 24
\(\frac{200+201}{201+202}=\frac{200}{201+202}+\frac{201}{201+201}\)
Mà \(201\frac{200}{201+202}\)
\(\frac{201}{202}>\frac{201}{201+202}\)
=> \(\frac{200}{201}+\frac{201}{202}>\frac{200+201}{201+202}\)
\(\frac{200}{201}+\frac{201}{202}=1,99...>1>\frac{401}{403}=\frac{200+201}{201+202}\)
\(\frac{200+201}{201+202}=\frac{200}{201+202}+\frac{201}{201+201}\)
Mà \(201< 201+202\Rightarrow\frac{200}{201}>\frac{200}{201+202}\)
\(\frac{201}{202}>\frac{201}{201+202}\)
Vậy \(\frac{200}{201}+\frac{201}{202}>\frac{200+201}{201+202}\)
199 - 200 + 201 - 202 + 203 - 204 + 205 - 206 + 207
= ( 199 - 200 ) + ( 201 - 202 ) + ( 203 - 204 ) + ( 205 - 206 ) + 207
= ( -1 ) + ( -1 ) + ( -1 ) + ( -1 ) + 207
= -4 + 207
= 203
199 - 200 + 201 - 202 + 203 - 204 + 205 - 206 + 207 = 203
Gọi d là UCLN(n,n+1)
Ta có:n+1 chia hết cho d
n chia hết cho d
=>(n+1)-n chia hết cho d
=>1 chia hết cho d
=>d=1
Vậy phân số n/n+1 tối giản
ta co:(n,n+1)=dn
talai co:(n+1)-n=1 chia het cho d suy ra d=1.vayn/n+1 toi gian
b)2014/2014*2015=2014:2014/2014*2015:2014=1/2015(rút gọn phân số)
2015/2015*2015=2015:2015/2015*2016:2015=1/2016(rút gọn phân số)
Mà 1/2015>1/2016
=>2014/2014*2015>2015/2015*2015
Ta có:
\(\frac{200+201}{201+202}=\frac{200}{201+202}+\frac{201}{201+202}\)
Do\(\frac{200}{201}>\frac{200}{201+202},\frac{201}{202}>\frac{201}{201+202}\)
\(\Rightarrow\frac{200}{201}+\frac{201}{202}>\frac{200}{201+202}+\frac{201}{201+202}\)
\(\Rightarrow\frac{200}{201}+\frac{201}{202}>\frac{200+201}{201+202}\)
Vậy\(\frac{200}{201}+\frac{201}{202}>\frac{200+201}{201+202}\)
\(\frac{201}{202}+\frac{202}{205}\)Và \(201+\frac{202}{202}+205\)
\(=\frac{201}{202}=\frac{201}{202}+\frac{1}{202}=\frac{202}{202}\)
\(\frac{202}{205}=\frac{202}{205}+\frac{3}{205}=\frac{205}{205}\)
\(201+1+205\)
Vậy \(1+1=2\)và \(407\)
=> \(\frac{201}{202}+\frac{202}{205}< 201+\frac{202}{202}+205\)
Ta có: \(\frac{201+202}{202+205}=\frac{201}{202+205}+\frac{202}{202+205}\)
Ta có: 202<202+205 => \(\frac{201}{202}>\frac{201}{202+205}\)(1)
205<202+205 => \(\frac{202}{205}>\frac{202}{202+205}\)(2)
Từ (1) và (2) => \(\frac{201}{202}+\frac{202}{205}>\frac{201+202}{202+205}\)