Đáp án:
2)
$4^{10}:8^{15}=(2^2)^{10}:(2^3)^{15}=2^{20}:2^{45}=2^{-25}$
3)
$\dfrac{4^7.3^4.9^6}{6^{13}}=\dfrac{(2^2)^7.3^4.(3^2)^6}{(2.3)^{13}}=\dfrac{2^{14}.3^{16}}{2^{13}.3^{13}}=2.3^3=54$
4)
$\dfrac{21^2.14.125}{35^3.6}=\dfrac{(3.7)^2.2.7.5^3}{(5.7)^3.2.3}=\dfrac{3^2.7^2.2.7.5^3}{5^3.7^3.2.3}=\dfrac{3^2.7^3.2.5^3}{5^3.7^3.2.3}=3$
5)
$\dfrac{73^2.54^2}{108^4}=\dfrac{73^2.54^2}{(54.2)^4}=\dfrac{73^2.54^2}{54^4.2^4}=\dfrac{73^2}{54^2.2^4}$
