Show me the standard form of 3 + 8y2

Adifferent website gives the cost for the first train as £56.88 and the second train as £20.11 with a £9.50 charge for cycle storage for the whole trip. how much would the journey cost you?

What is the average rate of change for this function for the interval from x=2 to x=4 ?

Can someone check if i did this right since i really want to make sure it’s correct. if you do you so much