18x : 2x = 81
(18 : 2)x = 81
9x = 81
9x = 92
=> x = 2
#Học tốt!!!
\(18^x:2^x=81\)
\(\left(18:2\right)^x=81\)
\(9^x=9^2\)
\(x=2\)
(18:2)x=81
9x=81
9x=92
suy ra x=2
ta có:
(18:2)x = 81
mà 18:2=9 nên ta có:
(9)2=81
vậy suy ra x = 2
\(18^x:2^x=81\)
\(\left(18:2\right)^x=81\)
\(9^x=81\)
\(9^x=9^2\)
\(\Rightarrow x=2\)
