Answer:
f(3) = 2
Step-by-step explanation:
Remark
The formula starts out as
f(x)= 2x - 4
So what is telling you is that were ever you see a variable on the right, it can from the x on the left.
If you change the variable on the left, you must also do it on the right.
f(3) = 2*3 -4
f(3) = 6-4
f(3) = 2
