Answer:
7n-3
Step-by-step explanation:
You find the difference, 11-4 is 7, 18-11 is 7 ect. This is how we get the 7n. And because it is a linear sequence, we won't have to worry about finding the second difference. So then you get 7 and minus it from the first term. 4-7 is -3. Which is were we get the last part of our equation from. And we can checn this by inputting the number 1, for the first term. 1 times 7 is 7, -3 which is 4. This shows it is right and your answer is 7n-3.