To solve for [tex]\( f(x) \)[/tex] when [tex]\( x = -5 \)[/tex] with the given function [tex]\( f(x) = 5x + 40 \)[/tex], follow these steps:
1. Substitute [tex]\( x = -5 \)[/tex] into the function [tex]\( f(x) \)[/tex]:
[tex]\[
f(-5) = 5(-5) + 40
\][/tex]
2. Calculate the product [tex]\( 5 \times -5 \)[/tex]:
[tex]\[
5 \times -5 = -25
\][/tex]
3. Add 40 to the result:
[tex]\[
-25 + 40 = 15
\][/tex]
Therefore, [tex]\( f(-5) = 15 \)[/tex].
So, the correct answer is 15.