Question

Câu 22: Tính giá trị biểu thức: A =\(\dfrac{2^{12}.3^5-4^6.9^2}{\left(2^2.3\right)^6+8^4.3^5}\)

                                                 B =\(\dfrac{5.4^{15}.9^9-4.3^{20}.8^9}{5.2^{10}.6^{12}-7.2^{29}.27^6}\)

Answer 1

giúp mình với ạ mai mình thi rồi huhu

Answer 2

\(A=\dfrac{2^{12}\cdot3^5-2^{12}\cdot3^4}{2^{12}\cdot3^6+2^{12}\cdot3^5}=\dfrac{2^{12}\cdot3^4\left(3-1\right)}{2^{12}\cdot3^5\left(3+1\right)}=\dfrac{1}{3}\cdot\dfrac{1}{2}=\dfrac{1}{6}\)

\(B=\dfrac{5\cdot2^{30}\cdot3^{18}-3^{20}\cdot2^{29}}{5\cdot2^{22}\cdot3^{12}-7\cdot2^{29}\cdot3^{18}}\)

\(=\dfrac{3^{18}\cdot2^{29}\left(5\cdot2-9\right)}{2^{22}\cdot3^{12}\left(5-7\cdot2^7\cdot3^6\right)}=\dfrac{3^6\cdot2^7}{5-7\cdot128\cdot3^6}\)