\(A=\frac{49^2\cdot3^{11}}{81^2\cdot21^5}\)
\(=\frac{\left(7^2\right)^2\cdot3^{11}}{\left(3^4\right)^2\cdot\left(3\cdot7\right)^5}\)
\(=\frac{7^4\cdot3^{11}}{3^8\cdot3^5\cdot7^5}\)
\(=\frac{7^4\cdot3^{11}}{3^{13}\cdot7^5}\)
\(=\frac{1}{3^2\cdot7}=\frac{1}{63}\)
Bài làm :
Ta có :
\(A=\frac{49^2\cdot3^{11}}{81^2\cdot21^5}\)
\(A=\frac{\left(7^2\right)^2\cdot3^{11}}{\left(3^4\right)^2\cdot\left(3\cdot7\right)^5}\)
\(A=\frac{7^4\cdot3^{11}}{3^8\cdot3^5\cdot7^5}\)
\(A=\frac{7^4\cdot3^{11}}{3^{13}\cdot7^5}\)
\(A=\frac{1}{3^2\cdot7}\)
\(A=\frac{1}{63}\)
Vậy A=1/63
\(A=\frac{49^2.3^{11}}{81^2.21^5}\)
\(=\frac{\left(7^2\right)^2.3^{11}}{\left(3^4\right)^2.\left(3.7\right)^5}\)
\(=\frac{7^4.3^{11}}{3^8.3^5.7^5}\)
\(=\frac{1}{3^2.7}\)
\(=\frac{1}{63}\)
Học tốt
\(\frac{49^2.3^{11}}{81^2.21^5}=\frac{\left(7^2\right)^2.3^{11}}{\left(3^4\right)^2.3^5.7^5}=\frac{7^4.3^{11}}{3^8.3^5.7^5}=\frac{1}{3^2.7}=\frac{1}{63}\)
học tốt