The first thing we must do for this case is to define a variable. We have then: n: unknown number. We write the algebraic expression: 13 - 4n For n = 3 we have: 13 - 4 (3) = 13 - 12 = 1 Answer: An expression that represents this phrase is: 13 - 4n its value if n = 3 is: 1
