To find out how many more boxes of hand sanitizer Mrs. Nelson needs, we first need to establish what she already has and how many she still needs.
She currently has 25 bottles and needs a total of 200 bottles. This means she needs:
\[ 200 - 25 = 175 \text{ bottles} \]
Since the bottles are sold in boxes of 20, we can let \( x \) represent the number of boxes she needs. Therefore, the equation to calculate the total number of bottles from the boxes can be written as:
\[ 20x + 25 = 200 \]
This equation indicates that 20 times the number of boxes (each containing 20 bottles) plus the 25 bottles she already has must equal 200 bottles.
Among the options you provided:
- 25 + 20x = 200 is the correct equation.
To summarize, Mrs. Nelson needs 175 more bottles, and to find the number of boxes needed, you would proceed to solve this equation:
\[ 20x + 25 = 200 \]
Subtract 25 from both sides:
\[ 20x = 175 \]
Now, divide by 20:
\[ x = \frac{175}{20} = 8.75 \]
Since she can't buy a fraction of a box, she would need to buy 9 boxes to meet or exceed her requirement.