To represent the condition that the total weight of two packages must not exceed 30 kg, you can use the following inequality:
Let \( x \) be the weight of the first package and \( y \) be the weight of the second package. The inequality representing the condition is:
\[ x + y \leq 30 \]
This inequality states that the sum of the weights of the two packages, \( x \) and \( y \), must be less than or equal to 30 kg.