If [tex]$f(x)=5x + 40$[/tex], what is [tex]$f(x)$[/tex] when [tex][tex]$x = -5$[/tex][/tex]?

A. -9
B. [tex]$-8$[/tex]
C. 7
D. 15



Answer :

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.