To determine which equation correctly represents the total cost [tex]\( y \)[/tex] of a child's toy considering the number of batteries used [tex]\( x \)[/tex], we need to follow these steps:
1. Identify the cost components:
- Battery cost: Each battery costs \[tex]$0.75.
- Toy cost: The toy itself costs \$[/tex]12.
2. Formulate the equation:
- The cost contribution from the batteries can be expressed as [tex]\( 0.75x \)[/tex], where [tex]\( x \)[/tex] is the number of batteries used.
- The fixed cost of the toy is \$12.
3. Combine these components into the total cost equation:
- The total cost [tex]\( y \)[/tex] will include both the variable cost from the batteries and the fixed cost of the toy.
Combining these components, we get:
[tex]\[ y = 0.75x + 12 \][/tex]
Therefore, the correct equation that represents the situation is:
[tex]\[ y = 0.75x + 12 \][/tex]
This matches the second equation in the provided choices. Thus, the correct answer is:
[tex]\[ \boxed{y = 0.75x + 12} \][/tex]
