2) rút gọn
\(A=\frac{3^6.45^4-15^{13}.5^{-9}}{27^4.25^3+45^6}\)
Rút gọn
B = \(\frac{3^6.45^4-15^{13}.5^{-9}}{27^4.25^3+45^6}\)
\(\frac{3^6\times45^4-15^{13}\times5^{-9}}{27^4\times25^3+45^6}\)
\(=\frac{3^6\times\left(3^2\times5\right)^4-\left(3\times5\right)^{13}\times5^{-9}}{\left(3^3\right)^4\times\left(5^2\right)^3+\left(3^2\times5\right)^6}\)
\(=\frac{3^6\times3^8\times5^4-3^{13}\times5^{13}\times5^{-9}}{3^{12}\times5^6+3^{12}\times5^6}\)
\(=\frac{3^{14}\times5^4-3^{13}\times5^4}{3^{12}\times5^6+3^{12}\times5^6}\)
\(=\frac{3^{13}\times5^4\times\left(3-1\right)}{2\times3^{12}\times5^6}\)
\(=\frac{3\times2}{2\times5^2}\)
\(=\frac{3}{25}\)
Tính:\(\frac{3^6.45^4.-15^{13}.5^{-9}}{27^4.25^3+45^6}\)
\(\dfrac{3^6.45^4-15^{13}.5^{-9}}{27^4.25^3+45^6}\)
\(\dfrac{3^6.45^4-15^{13}.5^{-9}}{27^4.25^3+45^6}\)
\(\dfrac{3^6.45^4-15^{13}.5^{-9}}{27^4.25^3+45^6}=\dfrac{3^6.3^85^4-3^{13}.5^{13}.5^{-9}}{3^{12}.5^6+3^{12}.5^6}\)
\(=\dfrac{3^{14}.5^4-3^{13}.5^4}{2.3^{12}.5^6}=\dfrac{3^{13}.5^4\left(3-1\right)}{2.3^{12}.5^6}\)
\(=\dfrac{3.2}{2.5^2}=\dfrac{3}{25}\)
rút gọn A=
\(\frac{3^6.45^4-3^{10}.15^3}{27^4.25^3+45^6}\)
\(\frac{3^6.45^4-15^{13}.5^{-9}}{27^4.25^3+45^6}=?\)
tính nhanh
\(\frac{3^6.45^4-15^{13}:5^9}{27^4.25^3+45^6}\)
\(\frac{3^6.45^4-15^{13}:5^9}{27^4.25^3+45^6}\)=\(\frac{3^{14}.5^4-3^{13}.5^4}{3^{12}.5^6+3^{12}.5^6}=\frac{3^{13}.5^4\left(3-1\right)}{3^{12}.5^6\left(1+1\right)}\)=\(\frac{3}{25}\)
tính:
\(E=\frac{3^6.45^4-15^{13}.5^{-9}}{27^4.25^3+45^6}\)
\(E=\frac{3^6.45^4-15^{13}.5^{-9}}{27^4.25^3+45^6}\)
\(E=\frac{3^6.3^8.5^4-3^{13}.5^{13}.5^{-9}}{3^{12}.5^6+3^{12}.5^6}\)
\(E=\frac{3^{14}.5^4-3^{13}.5^4}{3^{12}.5^6\left(1+1\right)}\)
\(E=\frac{3^{13}.5^4\left(3-1\right)}{3^{12}.5^6.2}\)
\(E=\frac{3}{25}\)
\(\frac{3^6.45^4-15^{13}.5^9}{27^4.25^3+45^6}\)