Bài 20.8 ; 20.11 ( SBT Vật lí 6 )
Giúp mình giải bài này nhé : (5.4^15.9^9-4.3^20.8^9) : (5.2^9.6^19-7.2^29.27^6)
Bài 1: a) tìm A : B biết
A= 5.4^15.9^9- 4.3^20.8^9
B= 5.2^9.6^19-7.2^29.276
b)tính C:D biết
C= 2181.729+243.81.27
D=3^2.9^2.243+18.243.324+729.729
\(A=5.4^{15}.9^9-4.3^{20}.8^9\)
\(A=5.2^{30}.3^{27}-2^2.3^{20}.2^{27}=2^{29}.3^{20}.\left(5.2.3^7-1\right)\)
\(A=2^{29}.3^{20}.\left(21870-1\right)=2^{29}.3^{20}.21869\)
tính: 5.4^15-9^9-4.3^20.8^9/5.2^9.6^19-7.2^29.2.7^6
đây là bài dạng phân số nên mình lấy dấu / làm thành phân sô xin quý vị thông cảm.
5.4^15-4.3^20.8^9/5.2^10-7.2^29.27.6
\(=\dfrac{5\cdot2^{30}-3^{20}\cdot2^{29}}{5\cdot2^{10}-7\cdot2^{30}\cdot3^3}\)
\(=\dfrac{2^{29}\left(5\cdot2-3^{20}\right)}{2^{10}\left(5\cdot1-7\cdot2^{20}\cdot3^3\right)}=\dfrac{2^{19}\cdot\left(10-3^{20}\right)}{5-189\cdot2^{20}}\)
5.4^15.9^9-4.3^20.8^9/5.2^10.6^19-7.2^29.27^6
5.4^15.9^9-4.3^20.8^9/5.2^29.9^10-7.2^29,27^6
5.4^15.9^9-4.3^20.8^9/5.2^9.6^19-7.2^29.27^6
\(\frac{5.4^{15}.9^9-4.3^{20}.8^9}{5.2^9.6^{19}-7.2^{29}.27^6}=\frac{5.2^{30}.3^{18}-2^2.2^{27}.3^{20}}{5.2^9.2^{19}.3^{19}-7.2^{29}.3^{18}}\)
\(=\frac{2^{29}.3^{18}\left(5.2-3^2\right)}{2^{28}.3^{18}.\left(5.3-7.2\right)}=\frac{2.1}{1}=2\)
5.4^15 9^9 - 4. 3^20.8^9
5.2^9.6^19-7.2^29.27^6
B = 5.415.99 - 4.320.89
B = 5.(22)15.(32)9- (22).320.(23)9
B = 5.230.318 - 229.320
B = 229.318( 5.2 - 9)
B = 229.318.(10-9)
B = 229.318
C = 5.4^15.9^9-4.3^20.8^9 / 5.2^9.6^19-7.2^29.27^6