need to show your work

two trains, traveling towards eachother, 720 miles apart
one train is traveling 40mph faster than other

planes pass after 45 mins (.75 hours)

how fast each plane traveling

Planes or trains ?

V1 : speed of the slowest plane (in mph)
V2 : speed of the fastest plane (in mph)
V2 = V1 + 40

720 miles covered by the planes in 0.75 hour.

D1 : distance covered by the slowest plane (in miles)
D2 : distance covered by the fastest plane (in miles)

720 = D1 + D2
D1 = 0.75 * V1
D2 = 0.75 * V2

So :
720 = 0.75.V1 + 0.75.V2
720/0.75 = V1 + V2
960 = V1 + V2
960 = V1 + V1 + 40
920 = 2.V1
V1 = 460 mph

Slowest planes travels at 460 mph, fastest at 500 mph.

You can also call V the sum of the speeds of each plane, and claim that 720 = 0.75.V, and then V = 960 mph, and get the result.

Unknown. There is no correlation between the trains' and planes' speeds.

wait, plane?

you need to include the starting distance between the boats

This

that

Youre literally offering people 37 fg to do your homework for you.

Youre asking someone to do your work for the equivalent of a few pennies in online gaming currency