To solve the problem, we need to establish an equation that represents the situation described. We know that the shelf can hold a total of 58 cans and currently has 39 cans that can still be added before it is full.
Let \( c \) represent the number of cans already on the shelf. Since the shelf can hold 58 cans, and there are 39 cans that can still be added, we can set up the equation:
\[ c + 39 = 58 \]
Now, we can solve for \( c \):
-
Subtract 39 from both sides of the equation: \[ c = 58 - 39 \]
-
Simplifying the right side gives: \[ c = 19 \]
So, there are 19 cans already on the shelf.
Looking at the options:
- c + 39 = 58 and −19 (incorrect)
- c − 58 = 39 and 97 (incorrect)
- c − 58 = 39 and 97 (incorrect)
- c + 39 = 58 and 19 (correct)
The correct equation is \( c + 39 = 58 \), and the answer is \( 19 \).