Question

if f(x)=(x^2-50) what is the value of (f(x)=-5)

Answer 1

it may x = - 5, so that the answer has come as 
f(-5) = (-5)^2 - 50 
       = 25 - 50 
       = -25,
                     OR
otherwise according to ur question f(x) =- 5 means,
-5 = x^2 - 50
x^2 = 50 -5 
x^2 = 45