To determine the value of [tex]\( f(x) \)[/tex] when [tex]\( x = -5 \)[/tex] for the function [tex]\( f(x) = 5x + 40 \)[/tex], follow these steps:
1. Start with the given function [tex]\( f(x) = 5x + 40 \)[/tex].
2. Substitute [tex]\( x = -5 \)[/tex] into the function:
[tex]\[
f(-5) = 5(-5) + 40
\][/tex]
3. Calculate [tex]\( 5(-5) \)[/tex]:
[tex]\[
5 \times -5 = -25
\][/tex]
4. Add 40 to the result:
[tex]\[
-25 + 40 = 15
\][/tex]
5. Therefore, the value of [tex]\( f(x) \)[/tex] when [tex]\( x = -5 \)[/tex] is [tex]\( 15 \)[/tex].
Hence, the correct answer is [tex]\( \boxed{15} \)[/tex].
