Answer :
Let's analyze the given phrase and the options step-by-step to determine the correct variable expression for the given words.
The phrase in question is: "The difference between the number of magic markers and 7 colored pencils."
1. Understanding the Phrase:
- The word "difference" in mathematics usually refers to a subtraction operation.
- The phrase indicates we need to find the difference between two quantities: the number of magic markers (denoted by \( m \)) and 7 colored pencils (represented by the number 7).
2. Constructing the Expression:
- Given that \( m \) represents the number of magic markers and we are subtracting the 7 colored pencils from it, the correct mathematical expression is \( m - 7 \).
3. Examining Each Option:
- Option A: \( m \div 7 \) – This represents dividing the number of magic markers by 7, which does not correspond to the "difference" phrase.
- Option B: \( m - 7 \) – This correctly represents the difference between the number of magic markers and 7 colored pencils.
- Option C: \( m + 7 \) – This represents adding the number of magic markers to 7, which is not what the phrase asks for.
- Option D: \( m \cdot 7 \) – This represents multiplying the number of magic markers by 7, which also does not correspond to the "difference" phrase.
4. Final Decision:
- Based on our analysis, the correct variable expression that represents the difference between the number of magic markers and 7 colored pencils is \( m - 7 \).
Thus, the correct answer is:
B. [tex]\( m - 7 \)[/tex]
The phrase in question is: "The difference between the number of magic markers and 7 colored pencils."
1. Understanding the Phrase:
- The word "difference" in mathematics usually refers to a subtraction operation.
- The phrase indicates we need to find the difference between two quantities: the number of magic markers (denoted by \( m \)) and 7 colored pencils (represented by the number 7).
2. Constructing the Expression:
- Given that \( m \) represents the number of magic markers and we are subtracting the 7 colored pencils from it, the correct mathematical expression is \( m - 7 \).
3. Examining Each Option:
- Option A: \( m \div 7 \) – This represents dividing the number of magic markers by 7, which does not correspond to the "difference" phrase.
- Option B: \( m - 7 \) – This correctly represents the difference between the number of magic markers and 7 colored pencils.
- Option C: \( m + 7 \) – This represents adding the number of magic markers to 7, which is not what the phrase asks for.
- Option D: \( m \cdot 7 \) – This represents multiplying the number of magic markers by 7, which also does not correspond to the "difference" phrase.
4. Final Decision:
- Based on our analysis, the correct variable expression that represents the difference between the number of magic markers and 7 colored pencils is \( m - 7 \).
Thus, the correct answer is:
B. [tex]\( m - 7 \)[/tex]