Question

Tính giá trị của biểu thức sau:(5*4^15*9^9-4*3^20*8^9):(5*2^9*6^19-7*2^29*27^6)

Answer 1

\(\dfrac{5.4^{15}.9^9-4.3^{20}.8^9}{5.2^9.6^{19}-7.2^{29}.27^6}\)

\(=\dfrac{5.\left(2^2\right)^{15}.\left(3^2\right)^9-2^2.3^{20}.\left(2^3\right)^9}{5.2^9.\left(2.3\right)^{19}-7.2^{29}.\left(3^3\right)^6}\)

\(=\dfrac{5.2^{30}.3^{18}-2^{29}.3^{20}}{5.2^{28}.3^{19}-7.2^{29}.3^{18}}=\dfrac{2^{29}.3^{18}\left(5.2-3^2\right)}{2^{28}.3^{18}\left(5.3-7.2\right)}\)

\(=\dfrac{2^{29}.3^{18}}{2^{28}.3^{18}}=2\)

Answer 2

bạn có thể ghi rõ r được không vậy ?