\(\frac{2^2.3^3.5^7}{2^3.3^4.5^6}=\frac{1.1.5}{2.3.1}=\frac{5}{6}\)

Làm tương tự 

\(\frac{6^5.35^7}{14^7.15^5}=\frac{2^5.3^5.5^7.7^7}{2^7.7^7.3^5.5^5}=\frac{5^2}{2^2}=\frac{25}{4}\)

\(\frac{75}{2}\)

\(=\frac{\left(2.3\right)^6.\left(5.7\right)^7}{\left(2.7\right)^4.\left(3.5\right)^5}=\frac{2^6.3^6.5^7.7^7}{2^4.7^4.3^5.5^5}=\frac{2^2.3.5^2.7^3}{1.1.1.1}=\left(4.25\right).3.7^3=100.3.343=102900\)

kiều bích huyền ghi sai đề làm bậy luôn 

3/20 + 1/6 = 19/60

\(\dfrac{3}{20}+\dfrac{1}{6}=\dfrac{9}{60}+\dfrac{10}{60}=\dfrac{19}{60}\)

21/15=21:3/15:3=7/5

11/121=11:11/121:11=1/11

27/72=27:9/72:9=3/8

\(\dfrac{21}{15}=\dfrac{7}{5};\dfrac{11}{121}=\dfrac{1}{11};\dfrac{27}{72}=\dfrac{3}{8}\)

\(\dfrac{21}{15}=\dfrac{21:3}{15:3}=\dfrac{7}{5}\)

\(\dfrac{11}{121}=\dfrac{11:11}{121:11}=\dfrac{1}{11}\)

\(\dfrac{27}{72}=\dfrac{27:9}{72:9}=\dfrac{3}{8}\)

1/1/3+3/1/4+4/1/5

=4/3+13/4+21/5

=?

\(\frac{\frac{5}{7}+\frac{6}{11}+\frac{7}{13}}{\frac{10}{7}+\frac{12}{11}+\frac{14}{13}}\)

\(=\frac{\frac{5}{7}+\frac{6}{11}+\frac{7}{13}}{2\left(\frac{5}{7}+\frac{6}{11}+\frac{7}{13}\right)}\)

\(=\frac{1}{2}\)