Me i really need the on these question

i will give 100 points !

What is the length of the segment joining the points at (4,5) and (6,-2) round to the nearest tenth if necessary

For f(x)=2x+3 and g(x)=x^2- 8 find (f+g) (x)

Marcus and cody both leave the park at the same time, but in opposite directions. if cody travels 6 mph faster than marcus and after 4 hours they are 64 miles apart, how fast is each traveling? solve using rare times time = distance.