rut gon 45^10:5^20/15
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Rut gon bieu thuc ( 2x like )
a)28^15 . 3^17
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84^16
b) 3^10 + 6^2
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5.3^8 + 20
Lời giải:
\(=\frac{5.2^2.2^{30}.3^{20}-2^2.3^{21}.2^{30}}{5.2.2^{20}.5^{10}.2^{20}.3^{20}-2^{31}.3^{21}}=\frac{5.2^{32}.3^{20}-2^{32}.3^{21}}{5^{11}.2^{41}.3^{20}-2^{31}.3^{21}}\\
=\frac{2^{32}.3^{20}(5-3)}{2^{31}.3^{20}(5^{11}.2^{10}-3)}\\
=\frac{2^{33}.3^{20}}{2^{31}.3^{20}(5^{11}.2^{10}-3)}=\frac{4}{5^{11}.2^{10}-3}\)
a)\(\frac{16}{20}=\frac{4}{5};\frac{9}{15}=\frac{3}{5}\)
Vì 4>3\(\Rightarrow\frac{4}{5}>\frac{3}{5}\) hay \(\frac{16}{20}>\frac{9}{15}\)
Vậy \(\frac{16}{20}>\frac{9}{15}\)
b) \(\frac{6}{8}=\frac{3}{4};\frac{3}{12}=\frac{1}{4}\)
Vì 3>1 \(\Rightarrow\frac{3}{4}>\frac{1}{4}\) hay \(\frac{6}{8}=\frac{3}{12}\)
Vậy \(\frac{6}{8}=\frac{3}{12}\)
c) \(\frac{15}{25}=\frac{3}{5};\frac{36}{45}=\frac{4}{5}\)
Vì 3<4 \(\Rightarrow\frac{3}{5}<\frac{4}{5}\) hay \(\frac{15}{25}<\frac{36}{45}\)
Vậy \(\frac{15}{25}<\frac{36}{45}\)