so sánh
\(\frac{1515}{1515}và\frac{2000}{1999}\)
so sánh :
\(\frac{111111}{666665}\)và\(\frac{1212+1313+1414+1515+1616}{1717+1818+1919+2020+2121}\)
Ai làm đúng và nhanh nhất mk k cho
cái thứ hai lớn hơn
Ta có : \(\frac{1212+1313+1414+1515+1616}{1717+1818+1919+2020+2121}=\frac{12+13+14+15+16}{17+18+19+20+21}=\frac{28\cdot\frac{5}{2}}{38\cdot\frac{5}{2}}=\frac{14}{19}\)
Dễ thấy \(\frac{111111}{666665}< \frac{1}{2}\) ( do 111111 < 666665/2 ) và \(\frac{14}{19}>\frac{1}{2}\) ( do 14 > 19/2 )
Vậy \(\frac{111111}{666665}< \frac{1212+1313+1414+1515+1616}{1717+1818+1919+2020+2121}\)
\(\frac{1515}{3131}\)và \(\frac{151515}{313131}\)
So sánh nhé mấy bn
so sánh 2 phân số 13/15 và 1313/1515
1313/1515=1313:101/1515:101=13/15
vay 13/15=1313/1515
Ta có:1313/1515=13.101/15.101=13/15
Vì 13/15=13/15 nên 13/15=1313/1515
So sánh: C=\frac{1999^2000+1/1999^1999+1} và D=\frac{1999^1999+1/1999^1998+1}
so sánh 1111/1212 và 1515/1616. ghi cả lời giải giúp mình nha
\(\dfrac{1111}{1212}\) và \(\dfrac{1515}{1616}\)
\(\dfrac{1111}{1212}=\dfrac{1111\times1616}{1212\times1616}=\dfrac{1795376}{1958592}\)
\(\dfrac{1515}{1616}=\dfrac{1515\times1212}{1616\times1212}=\dfrac{1836180}{1958592}\)
Vì: 1836180 > 1795376
=> \(\dfrac{1111}{1212}< \dfrac{1515}{1616}\)
\(\dfrac{1111}{1212}\) = \(\dfrac{1111:101}{1212:101}\) = \(\dfrac{11}{12}\)= 1 - \(\dfrac{1}{12}\) ; \(\dfrac{1515}{1616}\) =\(\dfrac{1515:101}{1616:101}\) = \(\dfrac{15}{16}\) = 1 -\(\dfrac{1}{16}\)
Vì \(\dfrac{1}{12}\) > \(\dfrac{1}{16}\) nên \(\dfrac{1111}{1212}\) < \(\dfrac{1515}{1616}\)
\(\dfrac{1111}{1212}=\dfrac{11}{12}=1-\dfrac{1}{12}\)
\(\dfrac{1516}{1516}=\dfrac{15}{16}=1-\dfrac{1}{16}\)
Vì: \(\dfrac{1}{12}>\dfrac{1}{16}\) nên \(1-\dfrac{1}{12}< 1-\dfrac{1}{16}\)
Vậy\(\dfrac{1111}{1212}< \dfrac{1515}{1616}\)
So sánh hai phân số sau:
12/15 và 1212/1515
Trước khi so sánh, ta phải rút gọn phân số \(\frac{1212}{1515}\)và \(\frac{12}{15}\)
Rút gọn P/S, ta có: \(\frac{1212:101}{1515:101}\)=\(\frac{12:3}{15:3}\)=\(\frac{3}{5}\)(1)
\(\frac{12:3}{15:3}=\frac{3}{5}\)(2)
Từ (1) và (2) => \(\frac{12}{15}=\frac{1212}{1515}\)
Ta có: \(\frac{12}{15}=\frac{12\div3}{15\div3}=\frac{4}{5}\)
\(\frac{1212}{1515}=\frac{1212\div303}{1515\div303}=\frac{4}{5}\)
Mà \(\frac{4}{5}=\frac{4}{5}\)
\(\Rightarrow\frac{12}{15}=\frac{1212}{1515}\)
Ta có :
1212/1515=12.102/15.101=12/15
Vì 12/15=12/15 =>12/15=1212/1515
vậy ...........
k mk nha
\(\frac{1414}{1515}x\frac{15}{14}=1\)
Đúng hay sai?
\(\frac{1414}{1515}x\frac{15}{14}=\frac{14}{15}\)
Đúng hay sai?
So sánh : \(\frac{1999×2000}{1999×2000+1}\)và \(\frac{2000×2001}{2000×2001+1}\)
Ta có: \(\frac{1999x2000}{1999x2000+1}=\frac{1999x2000+1-1}{1999x2000+1}=1-\frac{1}{1999x2000+1}\)
\(\frac{2000x2001}{2000x2001+1}=\frac{2000x2001+1-1}{2000x2001+1}=1-\frac{1}{2000x2001+1}\)
Nhận thấy: \(\frac{1}{1999x2000+1}>\frac{1}{2000x2001+1}\)=> \(1-\frac{1}{1999x2000+1}< 1-\frac{1}{2000x2001+1}\)
=> \(\frac{1999x2000}{1999x2000+1}=\frac{2000x2001}{2000x2001+1}\)
\(\frac{1999x2000}{1999x2000+1}< \frac{2000x2001}{2000x2001+1}\)
hay sap xep cac phan so theo thu tu tu be den lon len
a\(\frac{4343}{4444}\)\(\frac{1515}{1616}\)\(\frac{71}{72}\)\(\frac{93}{94}\)
b\(\frac{1717}{1515}\), \(\frac{127127}{125125}\),\(\frac{93}{91}\),\(\frac{111}{109}\)