Step-by-step explanation:
profit =20 rs
profit% = 20/80*100
=25%
F(4) value is 6.
I believe it would work like this:
f(x) is being turned into f(4), so 4 would equal x. Put 4 into the equation 3x-6, and you get 12-6, which gives you 6. So the value of f(4) is 6. I hope this helps!