Answer:
B. 5
Explanation:
Given expression;
n(n - x) = 25
From the given expression, x = 0
Substitute the value of x into the given equation and solve for n;
n(n - 0) = 25
this equation reduces to;
n(n) = 25
simplifying further to obtain the value of n;
n² = 25
n = √25
n = 5
Therefore, the correct option is B.