so sánh
\(\frac{12}{10}\) và \(\frac{6}{5}\)
\(\frac{13}{15}\) và \(\frac{232323}{252525}\)
\(\frac{1+2+3+4+5}{6+7+8+9+10}\)và \(\frac{11+12+13+14+15}{5+6+7+8+9}\)
So sánh nhé các bạn
Gợi ý: Rút gọn 2 ps, quy đồng rồi so sánh.
A=\(\frac{3^3}{1}-\frac{5^3}{3}+\frac{7^3}{6}-\frac{9^3}{10}+\frac{11^3}{15}-\frac{13^3}{21}+...+\frac{1993^3}{4950}\). So sánh A và B=814
So sánh các phân số sau:
a) \(\frac{13}{27}và\frac{1313}{2727}\)
b) \(\frac{-15}{23}và\frac{-151515}{232323}\)
GIÚP MK VS , MK ĐANG CẦN RẤT GẤP!
a)
\(\frac{13}{27}=\frac{13.101}{27.101}=\frac{1313}{2727}\)
=> \(\frac{13}{27}=\frac{1313}{2727}\)
b)
\(-\frac{15}{23}=-\frac{15.10101}{23.10101}=-\frac{151515}{232323}\)
=>\(-\frac{15}{23}=-\frac{151515}{232323}\)
a) \(\frac{1313}{2727}=\frac{1313:101}{2727:101}=\frac{13}{27}\)
Vậy \(\frac{13}{27}=\frac{1313}{2727}\)
b) \(-\frac{151515}{232323}=\frac{-151515:10101}{232323:10101}=-\frac{15}{23}\)
Vậy \(-\frac{15}{23}=-\frac{151515}{232323}\)
\(A=\frac{4}{10\cdot2}+\frac{6}{2\cdot20}+\frac{15}{5\cdot20}+\frac{5}{5\cdot40};B=\frac{3}{1\cdot5}+\frac{5}{13\cdot1}+\frac{11}{13\cdot3}+\frac{2}{3\cdot26}\)
So sánh A với B
So sánh các phân số sau
a) \(\frac{13}{27}\) và \(\frac{1313}{2727}\)
b) \(\frac{-15}{23}\) và \(\frac{151515}{232323}\)
a, \(\frac{1313}{2727}=\frac{13\cdot101}{27\cdot1001}=\frac{13}{27}\)
b,\(\frac{151515}{232323}=\frac{15.10101}{23.10101}=\frac{15}{23}\)
Bài 1 : So sánh
\(\left(\frac{1}{10}\right)^{15}\) và \(\left(\frac{3}{10}\right)^{20}\)
Bài 2 : So sánh
A = \(\left(\frac{13^{15}+1}{13^{16}+1}\right)\) và B = \(\left(\frac{13^{16}+1}{13^{17}+1}\right)\)
Bài 1:
Ta có:
\(\left(\frac{1}{10}\right)^{15}=\left(\frac{1}{5}\right)^{3.5}=\left(\frac{1}{125}\right)^5\)
\(\left(\frac{3}{10}\right)^{20}=\left(\frac{3}{10}\right)^{4.5}=\left(\frac{81}{10000}\right)^5\)
Lại có:
\(\frac{1}{125}=\frac{80}{10000}< \frac{81}{10000}\Rightarrow\left(\frac{1}{125}\right)^5< \left(\frac{81}{10000}\right)^5\)
\(\Rightarrow\left(\frac{1}{10}\right)^{15}< \left(\frac{3}{10}\right)^{20}\)
Bài 2:
Ta có:
\(A=\frac{13^{15}+1}{13^{16}+1}\Rightarrow13A=\frac{13^{16}+13}{13^{16}+1}=1+\frac{12}{13^{16}+1}\)
\(B=\frac{13^{16}+1}{13^{17}+1}\Rightarrow13B=\frac{13^{17}+13}{13^{17}+1}=1+\frac{12}{13^{17}+1}\)
Mà \(\frac{12}{13^{16}+1}>\frac{12}{13^{17}+1}\)
\(\Rightarrow1+\frac{12}{13^{16}+1}>1+\frac{12}{13^{17}+1}\)
\(\Rightarrow13A>13B\Rightarrow A>B\)
so sánh
\(\frac{12}{15}và\frac{-13}{-16}\)
So sánh A và B biết:
a) A =\(\frac{10^7+5}{10^7-8}\) B =\(\frac{10^8+6}{10^8-7}\)
B) A =\(\frac{15^{16}-13}{15^{16}+7}\) B = \(\frac{16^{17}-12}{16^{17}+8}\)
So sánh: \(\frac{252525}{373737}và\frac{272727}{353535}\)
\(\frac{252525}{373737}=\frac{252525:10101}{373737:10101}=\frac{25}{37}\)
\(\frac{272727}{353535}=\frac{272727:10101}{353535:10101}=\frac{27}{35}>\frac{27}{37}>\frac{25}{37}\)
vậy \(\frac{252525}{373737}
\(\frac{252525}{373737}=\frac{25.10101}{37.10101}=\frac{25}{37}=\frac{875}{1295}\)
\(\frac{272727}{353535}=\frac{27.10101}{35.10101}=\frac{27}{35}=\frac{999}{1295}\)
Vì \(\frac{875}{1295}
\(\frac{252525}{373737}=\frac{252525:10101}{373737:10101}=\frac{25}{37};\frac{272727}{353535}=\frac{272727:10101}{353535:10101}=\frac{27}{35}\)
=>25/37<27/35