A = \(\dfrac{72^3.5^{42}}{108^4}\)
= \(\dfrac{\left(2^3.3^2\right)^3.5^{42}}{\left(2^2.3^3\right)^4}\)
= \(\dfrac{2^9.3^6.5^{42}}{2^8.3^{12}}\)
= \(\dfrac{2.5^{42}}{3^6}\)
@trần phúc nguyên
B = \(\dfrac{45^3.20^4.18^2}{180^5}\)
= \(\dfrac{\left(3^2.5\right)^3\left(2^2.5\right)^4.\left(2.3^2\right)^2}{\left(2^2.3^2.5\right)^5}\)
= \(\dfrac{3^6.5^3.2^8.5^4.2^2.3^4}{2^{10}.3^{10}.5^5}\)
= \(\dfrac{3^{10}.5^7.2^{10}}{2^{10}.3^{10}.5^5}\)
= 25
@trần phúc nguyên
C = \(\dfrac{11.3^{22}.3^7-9^{15}}{\left(2.3^{14}\right)^2}\)
= \(\dfrac{11.3^{29}-\left(3^2\right)^{15}}{2^2.3^{28}}\)
= \(\dfrac{11.3^{29}-3^{30}}{2^2.3^{28}}\)
= \(\dfrac{3^{29}\left(11-3\right)}{2^2.3^{28}}\)
= \(\dfrac{33-9}{4}\)
= 6
@trần phúc nguyên