a) Tử số = 3^6.45^4−15^13.5^−9=3^6.(5.3^2)^4−(3.5)^13.5^−9=3^6.5^4.3^8−3^13.5^13.5^−9=3^14.5^4−3^13.5^4=3^13.5^4(3−1)=2.3^13.5^4
Mẫu số = 27^4.25^3+45^6=3^12.5^6+3^12.5^6=2.3^12.5^6
Phân số = 2.3^13.5^4/2.3^12.5^6=3/25
\(\frac{3^6.45^4-15^{13}.5^{-9}}{27^4.25^3+45^6}=\frac{3^6.\left(3^2.5\right)^4-\left(3.5\right)^{13}.5^{-9}}{3^{12}.5^6+\left(3^2.5\right)^6}\)
=\(\frac{3^6.3^8.5^4-3^{13}.5^{13}.5^{-9}}{3^{12}.5^6+3^{12}.5^6}\)
=\(\frac{3^{13}.3.5^4-3^{13}.5^4}{3^{12}.5^6.2}\)
= \(\frac{5^4.3^{13}.2}{3^{12}.5^6.2}=\frac{1.3}{5}=\frac{3}{5}\)
K mk nhé mn!!!!!!!