Final answer:
To find the value of the function f(x) = -4x^2 + 23 at x = -5, substitute -5 into the function and simplify to get f(-5) = -77.
Step-by-step explanation:
The student asked for the value of the function f(x) = -4x^2 + 23 when x = -5. To find this value, we simply substitute -5 into the function:
f(-5) = -4(-5)^2 + 23
f(-5) = -4(25) + 23
f(-5) = -100 + 23
f(-5) = -77
Therefore, the value of f(-5) is -77.