The first row represents the input. The second row represents the value that the function f assumes for each input above. The third row represents the value that the function g assumes for each input above.
To compute f(1), we look for 1 in the first row (third column) and we look for the correspondent value for f. In this case, we have f(1)=4
Similarly, we look for 3 in the first row (last column) and we look for the value of g. In this case, we have g(3)=3.
Now we can plug the values in the formula:
[tex]f(1)+2g(3) = 4+2\cdot 3 = 4+6=10[/tex]
