if ( f(x)=5x + 40 ), what is ( f(x) ) when ( x=-5 )?\n-9\n-8\n7\n15

Explanation:

Step1: Substitute (x = - 5) into the function

Substitute (x=-5) into (f(x)=5x + 40), we get (f(-5)=5\times(-5)+40).

Step2: Calculate the value

First, calculate (5\times(-5)=-25). Then, (f(-5)=-25 + 40). Since (-25+40=15).

Answer:

(15) (the fourth option)