Hello, thank you for taking the time to post your question!
The key on this type of question is to set up an algebraic expression that represents the information given in the question. On this one we have
f(x + h) = 4(x + h) + 3 because we’re substituting in (x + h) for the value of the variable on this expression
simplifying then that becomes
4x + 4h + 3
I hope that helps you get moving in a better direction on this type of question! Feel free to reach out if you have any additional questions beyond that :)
