Answer: n squared plus 10 n plus 25
Explanation:
To make the expression a perfect square:
add a term that is equal to half the coefficient of n, squared.
the coefficient of n is 10, so half of it is 5
add 5 squared, or 25, to the expression:
n squared plus 10 n plus 25
this expression can be factored into (n+5) squared, which is a perfect square.