2 câu trả lời
+ BCNN
27=3.7
36=2²
81 = 3^{4}
=> BCNN(27;36;81) = 2² . 3^{4} . 7 = 2268
+ ƯCLN
27 = 3 . 7
36 = 2² . 3²
81 = 3^{4}
=> UWCLN(27;36;81) = 3
Ta có : 27=3^3
36=2^2 .3^2
81=3^4
=>BCNNN(27,36,81)=3^4 .2^2=324
ƯCLN(27,36,81)=3^2=9