Answer :

To write an algebraic expression representing the product of 4 and a number [tex]\( n \)[/tex] being at most 51, we need to translate the phrase into a mathematical inequality.

1. Identify the variable: Let [tex]\( n \)[/tex] represent the unknown number.
2. Express the phrase "the product of 4 and a number [tex]\( n \)[/tex]" mathematically, which is [tex]\( 4n \)[/tex].
3. The phrase "is at most" translates to the inequality symbol "[tex]\(\leq\)[/tex]." This means that the expression should be less than or equal to 51.

Combining these parts, we get the following inequality:
[tex]\[ 4n \leq 51 \][/tex]

So, the algebraic expression that represents the product of 4 and a number [tex]\( n \)[/tex] is at most 51 is:
[tex]\[ 4n \leq 51 \][/tex]