Question

dada a função f (x)=3x+1 calcule: f (9)-f (1)

Answer 1

f(x)= 3x+1
f(9) = 3.9+1 
f(9) = 28

f(1) = 3.1+1
f(1) = 4

f(9)-f(1)= 28-4
f(9)-f(1) = 24