\(\frac{15.3^{11}+4.27^4}{9^7}\)

\(=\frac{5.3.3^{11}+4.\left(3^3\right)^4}{\left(3^2\right)^7}\)

\(=\frac{5.3^{12}+4.3^{12}}{3^{14}}\)

\(=\frac{3^{12}.\left(5+4\right)}{3^{14}}\)

\(=\frac{3^{12}.9}{3^{14}}\)

\(=\frac{3^{12}.3^2}{3^{14}}\)

\(=\frac{3^{14}}{3^{14}}\)

\(=1\)

Chúc bạn học tốt !!! 

\(A=\frac{15.3^{11}+4.27^4}{9^7}\)

\(\Rightarrow\frac{3.5.3^{11}+4.3^{3.4}}{3^{2.7}}\)

\(\Rightarrow\frac{3^{12}.5+3^{12}.4}{3^{14}}\)

\(\Rightarrow\frac{3^{12}\left(5+4\right)}{3^{14}}\)

\(\Rightarrow\frac{9}{3^2}=\frac{9}{9}=1\)

Vậy ....

thanks ban

= 5.3.3^11+4.(3^3)^4/(3^2)^7

= 5.3^12+4.3^12/3^14

= 3^12.(5+4)/3.3^12.3^2

= 3^12.9/3^12.9 = 1

k mk nha

Chứng minh à ?        

\(A=\frac{15.3^{11}+4.27^4}{9^7}=\frac{3.5.3^{11}+4.3^{3.4}}{3^{2.7}}=\frac{3^{12}.5+3^{12}.4}{3^{14}}=\frac{3^{12}\left(5+4\right)}{3^{14}}=\frac{9}{3^2}=\frac{9}{9}=1\)

-11/15.20/23+-11/15.3/23+-34/15

\(=\frac{-11}{15}\left(\frac{20}{23}+\frac{3}{23}\right)+\frac{-34}{15}\)

\(=\frac{-11}{15}.1+\frac{-34}{15}\)

\(=\frac{-45}{15}=-3\)

\(\frac{-11}{15}.\frac{20}{23}+\frac{-11}{15}.\frac{3}{23}+\frac{-34}{15}\)

\(=\frac{-11}{15}.\left(\frac{20}{23}+\frac{3}{23}\right)+\frac{-34}{15}\)

\(=\frac{-11}{15}.1+\frac{-34}{15}\)

\(=\frac{-11+\left(-34\right)}{15}\)

\(=\frac{-45}{15}\)

\(=-3\)

Study well ! >_<