Question 19
Professor M. A. Luco wrote the expression
$$
\frac{n^{2}-5 n+4}{n-4}
$$
on the board. He then told the students that $n$ may be any natural number except $4$.
a) What is the value of the expression for $n=1$?
b) Marcos substituted a natural number for $n$ and found that the value of the expression is $5$. Which number did he substitute?
c) Which natural numbers cannot be the numerical value of the expression?
$$
\frac{n^{2}-5 n+4}{n-4}
$$
on the board. He then told the students that $n$ may be any natural number except $4$.
a) What is the value of the expression for $n=1$?
b) Marcos substituted a natural number for $n$ and found that the value of the expression is $5$. Which number did he substitute?
c) Which natural numbers cannot be the numerical value of the expression?