Question

Find f(-5) if f(n) = n3 + 3n2 A) -50 B) -7 C) 0 D) 22

Answer 1

F(n) = n^3 + 3n^2
​substitute the f(-5)
​f(-5) = (-5)^3 + 3(-5)^2
solve 
f(-5) = -125 + 75
f(-5) = -50

​That is the solution
​A.) -50

​Hope this helps :)

Answer 2

$f(-5) = (-5)^{3} + 3(-5)^{2}$
$f(-5) = -125 + 3(25)$
$f(-5) = -125 + 75$
$= -50$