There appears to be a mistake in the problem. In cases like this, I like to suggest you ask your teacher to show the class how to work this problem. Let's follow it through.
Given
f(x) = 3x+4 . . . . . as shown in a table
g(x) = 2f(x) +3
Find
g(4)
Solution
[tex]g(x)=2f(x)+3\\g(4)=2f(4)+3\\g(4)=2\cdot 16+3\qquad\text{the table shows f(4)=16}\\g(4)=32+3\\\\g(4)=35[/tex]
Alternatively, we can use the formula we created for f(x).
[tex]g(x)=2f(x)+3\\g(x)=2(3x+4)+3\\g(x)=6x+8+3\\g(x)=6x+11\\g(4)=6\cdot 4+11=24+11\\\\g(4)=35[/tex]
Either way, g(4) = 35.
