So sánh
a) \(\left(\frac{1}{80}\right)^7\) với \(\left(\frac{1}{243}\right)^6\)
b) \(\left(\frac{3}{8}\right)^5\)với \(\left(\frac{5}{243}\right)^3\)
So sánh:
a, \(\left(\frac{1}{80}\right)^7\) với \(\left(\frac{1}{243}\right)^6\)
b, \(\left(\frac{3}{8}\right)^5\) với \(\left(\frac{5}{243}\right)^3\)
a) 80<243 nên \(\frac{1}{80}>\frac{1}{243}\)
\(\Rightarrow\left(\frac{1}{80}\right)^7>\left(\frac{1}{243}\right)^7\) mà \(\left(\frac{1}{243}\right)^7>\left(\frac{1}{243}\right)^6\)
Nên \(\left(\frac{1}{80}\right)^7>\left(\frac{1}{243}\right)^6\)
b) Ta so sánh \(\frac{3}{8}\) với \(\frac{5}{243}\)
Ta có: \(\frac{3}{8}=\frac{3.243}{8.243}=\frac{729}{1944}\)
\(\frac{5}{243}=\frac{5.8}{243.8}=\frac{40}{1944}\)
Suy ra: \(\frac{3}{8}>\frac{5}{243}\)
\(\Rightarrow\left(\frac{3}{8}\right)^5>\left(\frac{5}{243}\right)^5\) mà \(\left(\frac{5}{243}\right)^5>\left(\frac{5}{243}\right)^3\)
Nên \(\left(\frac{3}{8}\right)^5>\left(\frac{5}{243}\right)^3\)
So sánh:
a)\(\left(\frac{1}{80}\right)^7và\left(\frac{1}{243}\right)^6\)
b)\(\left(\frac{3}{8}\right)^5và\left(\frac{5}{243}\right)^3\)
So Sánh
a, \(\left(\frac{1}{8}\right)^7;\left(\frac{1}{243}\right)^6\)
b,\(\left(\frac{3}{8}\right)^5;\left(\frac{5}{243}\right)^3\)
\(a,\left(\frac{1}{8}\right)^7>\left(\frac{1}{81}\right)^7=\left(\frac{1}{3^4}\right)^7=\frac{1}{3^{28}}\)
\(\left(\frac{1}{234}\right)^6=\left(\frac{1}{3^5}\right)^6=\frac{1}{3^{30}}\)
Vì \(\frac{1}{3^{28}}>\frac{1}{3^{30}}\)nên \(\left(\frac{1}{80}\right)^7>\left(\frac{1}{243}\right)^8\)
\(b,\left(\frac{3}{5}\right)^5=\left(\frac{3}{2^3}\right)^5=\frac{243}{2^{15}};\)
\(\left(\frac{5}{243}\right)^3=\left(\frac{5}{3^5}\right)^3=\frac{125}{3^{15}}\)
Chọn phân số \(\frac{243}{3^{15}}\)làm phân số trung gian để so sánh hai phân số trên , ta thấy :
\(\frac{243}{2^{15}}>\frac{243}{3^{15}}>\frac{125}{3^{15}}\)
=> \(\frac{243}{2^{15}}>\frac{125}{3^{15}}\)
Từ đó => \(\left(\frac{3}{8}\right)^5>\left(\frac{5}{243}\right)^3\)
\(So\)\(sanh\):
a)\(\left(\frac{1}{80}\right)^7\)và\(\left(\frac{1}{243}\right)^6\)
b)\(\left(\frac{3}{8}\right)^5\)và \(\left(\frac{5}{243}\right)^3\)
so sánh:
a)\(\left(\frac{1}{80}\right)^7và\left(\frac{1}{243}\right)^6\)
b)\(\left(\frac{3}{8}\right)^5và\left(\frac{5}{243}\right)^3\)
giải chi tiết cho mk nha!!!
So sánh
a)\(\left(\frac{1}{80}\right)^7\)và \(\left(\frac{1}{243}\right)^6\)
b)\(\left(\frac{3}{8}\right)^5\)và \(\left(\frac{5}{243}\right)^3\)
c) \(\frac{10^{11}-1}{10^{12}-1}\)và \(\frac{10^{10}+1}{10^{11}+1}\)
1:So sánh:\(\left(\frac{1}{80}\right)^7\) và\(\left(\frac{1}{243}\right)^6\)
2:So sánh:\(\left(\frac{3}{8}\right)^5\)và\(\left(\frac{5}{243}\right)^3\)
làm nhanh giúp mình nhé!
SO SÁNH
\(\left(\frac{1}{80}\right)^7va\left(\frac{1}{243}\right)^6\)
\(\left(\frac{3}{5}\right)^5va\left(\frac{5}{243}\right)^3\)
\(\frac{-22}{35}va\frac{-103}{177}\)
\(\frac{84}{-83}va\frac{-337}{331}\)
So sánh \(\left(\frac{1}{80}\right)^7\) với \(\left(\frac{1}{243}\right)^6\)
\(\left(\frac{1}{80}\right)^7>\left(\frac{1}{81}\right)^7=\left(\frac{1}{3^4}\right)^7=\frac{1^7}{\left(3^4\right)^7}=\frac{1}{3^{28}}\)
\(\left(\frac{1}{243}\right)^6=\left(\frac{1}{3^5}\right)^6=\frac{1^6}{\left(3^5\right)^6}=\frac{1}{3^{30}}\)
Vì \(\frac{1}{3^{28}}>\frac{1}{3^{30}}\) nên \(\left(\frac{1}{80}\right)^7>\left(\frac{1}{243}\right)^6\)