Let's define the variables for the number of children and adults attending the party:
- Let \( c \) represent the number of children.
- Let \( a \) represent the number of adults.
According to the problem, we have the following information regarding the costs:
- The fixed cost for the party is $150.
- The cost per child is $10.50, so for \( c \) children, the cost is \( 10.50c \).
- The cost per adult is $5.50, so for \( a \) adults, the cost is \( 5.50a \).
The total cost of the party can be expressed as:
\[ \text{Total Cost} = 150 + 10.50c + 5.50a \]
Since Meha's aunt has a budget of $300, the total cost must not exceed this budget:
\[ 150 + 10.50c + 5.50a \leq 300 \]
Next, we also need to account for the requirement that there must be at least one adult and at least one child at the party. This can be expressed with the following inequalities:
\[ c \geq 1 \quad (at , least , one , child) \] \[ a \geq 1 \quad (at , least , one , adult) \]
Combining everything together, the set of inequalities representing this situation is:
- \( 150 + 10.50c + 5.50a \leq 300 \)
- \( c \geq 1 \)
- \( a \geq 1 \)
Thus, the two-variable inequality that represents the cost constraint is:
\[ 10.50c + 5.50a \leq 150 \]
with the conditions \( c \geq 1 \) and \( a \geq 1 \).