One can solve this by first using order of operations, and then combining like terms.
First is parenthesis
9x + 2x(9) - 2(9x)
Now we do the multiplication
9x + 18x - 18x
Now we combine like terms
9x
A=4-3b
subtract 4 from both sides
a-4=-3b
divide by -3 for both sides
(a-4)/-3 = b
D = vt
Distance traveled by train
d = 55t
Distance traveled by plane
d = 285t
Total distance
d = 1020
So, you do:
distance traveled by plane + distance traveled by train = total distance
(55t) + (285t) = 1020
Solve for t
t = 3 hours
t is the time traveled by each so 3 hrs traveled by train and 3 hrs traveled by plane
Total time = 3 + 3 = 6 hours
I think the answer is x=60