There is only one phrase for an algebraic expression that involves subtraction or division. For example, “4 – p” can be written as “four minus a number” but not “a number minus four.”
Explain why.
The reason "4 - p" can be written as "four minus a number" but not "a number minus four" is because of the order in which subtraction operations are performed. When performing subtraction, you start with the first number and then subtract the second number from it. In this case, "4 - p" means subtracting the value of p from 4.
If we were to write it as "a number minus four," it would imply subtracting 4 from the unknown value, which is not possible since we don't know the specific value of the number. Subtraction operations need to follow a specific order, where the first number is known and the second number is the one being subtracted.
To explain it mathematically, we can write "4 - p" as:
Subtract the value of p from 4.
Since we don't know the value of p, it remains as a variable or unknown number.