3:
a: \(938=9\cdot10^2+3\cdot10+8\)
b: \(50689=5\cdot10^4+6\cdot10^2+8\cdot10+9\)
c: \(\overline{ab0d}=a\cdot10^3+b\cdot10^2+d\)
d: \(202300=2\cdot10^5+2\cdot10^3+3\cdot10^2\)
Bài 2:
a) \(7^{19}\cdot7^{14}\)
\(=7^{19+14}\)
\(=7^{33}\)
b) \(3^{15}:3^7\)
\(=3^{15-7}\)
\(=3^8\)
c) \(6^{25}\cdot36\)
\(=6^{25}\cdot6^2\)
\(=6^{25+2}\)
\(=6^{27}\)
d) \(2^{18}:8\)
\(=2^{18}:2^3\)
\(=2^{18-3}\)
\(=2^{15}\)
e) \(2^{50}:\left(2^6\cdot16\right)\)
\(=2^{50}:\left(2^6\cdot2^4\right)\)
\(=2^{50}:2^{10}\)
\(=2^{50-10}\)
\(=2^{40}\)
f) \(3^9\cdot3^{11}:81\)
\(=3^9\cdot3^{11}:3^4\)
\(=3^{9+11-4}\)
\(=3^{16}\)
