Answer:
- f(2) = 0.5(2) +3.4
 - f(3.5) = 0.5(3.5) +3.4
 - f(15) = 0.5(15) +3.4
 - f(21.3) = 0.5(21.3) +3.4
 
Explanation:
Put the given weight where x is in the function definition. You're only asked for the expression, not its value.
- f(2) = 0.5(2) +3.4
 - f(3.5) = 0.5(3.5) +3.4
 - f(15) = 0.5(15) +3.4
 - f(21.3) = 0.5(21.3) +3.4