#### Answer

36

#### Work Step by Step

Multiples of 9: 9, 18, 27, 36, 45
In order to find the LCM of 4 and 9, we must find the first multiple of 9 that is also divisible by 4.
9, 18, and 27 are not divisible by 4.
$36\div4=9$
Therefore, 36 is the LCM of 4 and 9.