Answer:
23
Step-by-step explanation:
If you have something that says it is the f(x) or just f(something) then that is just telling you what the x equals. In this case, x=4 so you plug that into the equation.
This gives you f(4)=4(4)+7. From here, you will use the order of operations to solve.
f(4)=4*4+7
f(4)=16+7
f(4)=23
