Which expression does not represent "the sum of n and 6"?

1. 6+n
2. n+6
3. 6n

Which one is true about the hexagons ?

Moira has a canvas that is 8 inches by 10 inches. she wants to paint a line diagonally from the top left corner to the bottom right corner. approximately how long will the diagonal line be?

Precalculus question, image attached.